[ietf-smtp] Re: Examples of pseudonymous email services

Hector Santos <[email protected]> Tue, 28 May 2024 16:26:59 -0400
Newsgroups gmane.ietf.smtp
Message-ID <[email protected]>
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> On May 28, 2024, at 12:28=E2=80=AFPM, Jeremy Harris <[email protected]> =
wrote:
>=20
> On 28/05/2024 17:00, Dave Crocker wrote:
>> What are some examples of this being done?
>=20
> I can't tell what you asking for with "what are...".

To me, the term =E2=80=9Cpseudonymous" means there is still =
accountability with the usage of an obscure user ID. It is not =
completely hidden, and traceability is available. Therefore, I consider =
the term more like or closer to =E2=80=9Calias=E2=80=9D as opposed to a =
pure =E2=80=9Canonymous=E2=80=9D ID with little or no traceability.

> The private provider I help operate does it, by adding
> an entry into the DB used for mapping aliases to accounts.
> The receiving MTA uses the existence of an alias for
> deciding to accept or reject inbound messages.
> The MDA uses the mapping to find a file to deliver to.

+1. I agree, it is pretty traditional. In the early days with UUCP, =
acceptance, rejection, and bounces were all done post-transfer of data. =
With the introduction of SMTP and its nimbler implementations, we now =
have the flexibility to use dynamic shims and hooks for immediate RCPT =
TO: temporary or permanent responses.   Today,  higher overhead SMTP =
sessions that include:

Connect: IP Geo Location filtering, Rate Limiting
Helo/Ehlo: Stronger Client Host Name filtering
Mail From: SPF checking of the return-path and possibly the Client Host =
Name
Rcpt To: User DB check for direct vs remote address (requires =
authorization)
DATA Filtering: DKIM, ADSP, ATPS, DMARC, ARC, =E2=80=9CSpam Words=E2=80=9D=
 =E2=80=9CSpam Assassin=E2=80=9D filtering possibilities
(What is your current SMTP session residence time?  .5ms?  1-3 or more =
secs?)

The Return Path is checked in many ways, with the most successful being =
CBV (Call Back Verifier). Despite its controversy, it remains effective. =
However, we still need to address the issue of compliant bad actors. =
Even if a sender adheres to all rules from SPF to DMARC, anonymous names =
can still pose a problem.

All the best,
Hector Santos=

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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; =
charset=3Dutf-8"></head><body style=3D"overflow-wrap: break-word; =
-webkit-nbsp-mode: space; line-break: after-white-space;"><div =
dir=3D"auto" style=3D"overflow-wrap: break-word; -webkit-nbsp-mode: =
space; line-break: after-white-space;"><div dir=3D"auto" =
style=3D"overflow-wrap: break-word; -webkit-nbsp-mode: space; =
line-break: after-white-space;"><div><br><blockquote type=3D"cite"><div>On=
 May 28, 2024, at 12:28=E2=80=AFPM, Jeremy Harris =
&lt;[email protected]&gt; wrote:</div><br =
class=3D"Apple-interchange-newline"><div><div>On 28/05/2024 17:00, Dave =
Crocker wrote:<br><blockquote =
type=3D"cite">What&nbsp;are&nbsp;some&nbsp;examples&nbsp;of&nbsp;this&nbsp=
;being&nbsp;done?<br></blockquote><br>I can't tell what you asking for =
with "what =
are...".<br></div></div></blockquote><div><br></div><div><span =
style=3D"color: rgb(13, 13, 13); font-family: ui-sans-serif, =
-apple-system, system-ui, &quot;Segoe UI&quot;, Roboto, Ubuntu, =
Cantarell, &quot;Noto Sans&quot;, sans-serif, Helvetica, &quot;Apple =
Color Emoji&quot;, Arial, &quot;Segoe UI Emoji&quot;, &quot;Segoe UI =
Symbol&quot;; font-size: 16px; orphans: 2; white-space: pre-wrap; =
widows: 2; background-color: rgb(255, 255, 255);">To me, the term =
=E2=80=9Cpseudonymous" means there is still accountability with the =
usage of an obscure user ID. It is not completely hidden, and =
traceability is available. Therefore, I consider the term more like or =
closer to =E2=80=9Calias=E2=80=9D as opposed to a pure =E2=80=9Canonymous=E2=
=80=9D ID with little or no =
traceability.</span></div><div><div><br></div></div><blockquote =
type=3D"cite"><div><div>The private provider I help operate does it, by =
adding<br>an entry into the DB used for mapping aliases to =
accounts.<br>The receiving MTA uses the existence of an alias =
for<br>deciding to accept or reject inbound messages.<br>The MDA uses =
the mapping to find a file to deliver =
to.<br></div></div></blockquote><div><br></div><div><p style=3D"font-size:=
 16px; white-space: pre-wrap; border: 0px solid rgb(227, 227, 227); =
box-sizing: border-box; margin: 0px 0px 1.25em; color: rgb(13, 13, 13); =
font-family: ui-sans-serif, -apple-system, system-ui, &quot;Segoe =
UI&quot;, Roboto, Ubuntu, Cantarell, &quot;Noto Sans&quot;, sans-serif, =
Helvetica, &quot;Apple Color Emoji&quot;, Arial, &quot;Segoe UI =
Emoji&quot;, &quot;Segoe UI Symbol&quot;; font-variant-ligatures: =
normal; orphans: 2; widows: 2; background-color: rgb(255, 255, 255); =
text-decoration-thickness: initial; text-decoration-style: initial; =
text-decoration-color: initial;">+1. I agree, it is pretty traditional. =
In the early days with UUCP, acceptance, rejection, and bounces were all =
done post-transfer of data. With the introduction of SMTP and its =
nimbler implementations, we now have the flexibility to use dynamic =
shims and hooks for immediate <code style=3D"border: 0px solid rgb(227, =
227, 227); box-sizing: border-box; --tw-border-spacing-x: 0; =
--tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; font-feature-settings: =
normal; font-size: 0.875em; font-variation-settings: normal; =
font-weight: 600; font-family: ui-monospace, SFMono-Regular, &quot;SF =
Mono&quot;, Menlo, Consolas, &quot;Liberation Mono&quot;, monospace =
!important;">RCPT TO: temporary or permanent </code>responses.   Today,  =
higher overhead SMTP sessions that include:</p><ul style=3D"font-size: =
16px; white-space: pre-wrap; border: 0px solid rgb(227, 227, 227); =
box-sizing: border-box; list-style: outside; margin: 1.25em 0px; =
padding: 0px 0px 0px 1.625em; color: rgb(13, 13, 13); font-family: =
ui-sans-serif, -apple-system, system-ui, &quot;Segoe UI&quot;, Roboto, =
Ubuntu, Cantarell, &quot;Noto Sans&quot;, sans-serif, Helvetica, =
&quot;Apple Color Emoji&quot;, Arial, &quot;Segoe UI Emoji&quot;, =
&quot;Segoe UI Symbol&quot;; font-variant-ligatures: normal; orphans: 2; =
widows: 2; background-color: rgb(255, 255, 255); =
text-decoration-thickness: initial; text-decoration-style: initial; =
text-decoration-color: initial;"><li style=3D"border: 0px solid rgb(227, =
227, 227); box-sizing: border-box; --tw-border-spacing-x: 0; =
--tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-bottom: 0.5em; =
margin-top: 0.5em; padding-left: 0.375em;"><strong style=3D"border: 0px =
solid rgb(227, 227, 227); box-sizing: border-box; --tw-border-spacing-x: =
0; --tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-top: 1.25em; =
margin-bottom: 1.25em;">Connect:</strong> IP Geo Location filtering, =
Rate Limiting</li><li style=3D"border: 0px solid rgb(227, 227, 227); =
box-sizing: border-box; --tw-border-spacing-x: 0; --tw-border-spacing-y: =
0; --tw-translate-x: 0; --tw-translate-y: 0; --tw-rotate: 0; =
--tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; --tw-scale-y: 1; =
--tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-bottom: 0.5em; =
margin-top: 0.5em; padding-left: 0.375em;"><strong style=3D"border: 0px =
solid rgb(227, 227, 227); box-sizing: border-box; --tw-border-spacing-x: =
0; --tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-top: 1.25em; =
margin-bottom: 1.25em;">Helo/Ehlo:</strong> Stronger Client Host Name =
filtering</li><li style=3D"border: 0px solid rgb(227, 227, 227); =
box-sizing: border-box; --tw-border-spacing-x: 0; --tw-border-spacing-y: =
0; --tw-translate-x: 0; --tw-translate-y: 0; --tw-rotate: 0; =
--tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; --tw-scale-y: 1; =
--tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-bottom: 0.5em; =
margin-top: 0.5em; padding-left: 0.375em;"><strong style=3D"border: 0px =
solid rgb(227, 227, 227); box-sizing: border-box; --tw-border-spacing-x: =
0; --tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-top: 1.25em; =
margin-bottom: 1.25em;">Mail From:</strong> SPF checking of the =
return-path and possibly the Client Host Name</li><li style=3D"border: =
0px solid rgb(227, 227, 227); box-sizing: border-box; =
--tw-border-spacing-x: 0; --tw-border-spacing-y: 0; --tw-translate-x: 0; =
--tw-translate-y: 0; --tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; =
--tw-scale-x: 1; --tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; =
--tw-pinch-zoom: ; --tw-scroll-snap-strictness: proximity; =
--tw-gradient-from-position: ; --tw-gradient-via-position: ; =
--tw-gradient-to-position: ; --tw-ordinal: ; --tw-slashed-zero: ; =
--tw-numeric-figure: ; --tw-numeric-spacing: ; --tw-numeric-fraction: ; =
--tw-ring-inset: ; --tw-ring-offset-width: 0px; --tw-ring-offset-color: =
#fff; --tw-ring-color: rgba(69,89,164,0.5); --tw-ring-offset-shadow: 0 0 =
transparent; --tw-ring-shadow: 0 0 transparent; --tw-shadow: 0 0 =
transparent; --tw-shadow-colored: 0 0 transparent; --tw-blur: ; =
--tw-brightness: ; --tw-contrast: ; --tw-grayscale: ; --tw-hue-rotate: ; =
--tw-invert: ; --tw-saturate: ; --tw-sepia: ; --tw-drop-shadow: ; =
--tw-backdrop-blur: ; --tw-backdrop-brightness: ; =
--tw-backdrop-contrast: ; --tw-backdrop-grayscale: ; =
--tw-backdrop-hue-rotate: ; --tw-backdrop-invert: ; =
--tw-backdrop-opacity: ; --tw-backdrop-saturate: ; --tw-backdrop-sepia: =
; --tw-contain-size: ; --tw-contain-layout: ; --tw-contain-paint: ; =
--tw-contain-style: ; margin-bottom: 0.5em; margin-top: 0.5em; =
padding-left: 0.375em;"><strong style=3D"border: 0px solid rgb(227, 227, =
227); box-sizing: border-box; --tw-border-spacing-x: 0; =
--tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-top: 1.25em; =
margin-bottom: 1.25em;">Rcpt To:</strong> User DB check for direct vs =
remote address (requires authorization)</li><li style=3D"border: 0px =
solid rgb(227, 227, 227); box-sizing: border-box; --tw-border-spacing-x: =
0; --tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-bottom: 0.5em; =
margin-top: 0.5em; padding-left: 0.375em;"><strong style=3D"border: 0px =
solid rgb(227, 227, 227); box-sizing: border-box; --tw-border-spacing-x: =
0; --tw-border-spacing-y: 0; --tw-translate-x: 0; --tw-translate-y: 0; =
--tw-rotate: 0; --tw-skew-x: 0; --tw-skew-y: 0; --tw-scale-x: 1; =
--tw-scale-y: 1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; =
--tw-scroll-snap-strictness: proximity; --tw-gradient-from-position: ; =
--tw-gradient-via-position: ; --tw-gradient-to-position: ; --tw-ordinal: =
; --tw-slashed-zero: ; --tw-numeric-figure: ; --tw-numeric-spacing: ; =
--tw-numeric-fraction: ; --tw-ring-inset: ; --tw-ring-offset-width: 0px; =
--tw-ring-offset-color: #fff; --tw-ring-color: rgba(69,89,164,0.5); =
--tw-ring-offset-shadow: 0 0 transparent; --tw-ring-shadow: 0 0 =
transparent; --tw-shadow: 0 0 transparent; --tw-shadow-colored: 0 0 =
transparent; --tw-blur: ; --tw-brightness: ; --tw-contrast: ; =
--tw-grayscale: ; --tw-hue-rotate: ; --tw-invert: ; --tw-saturate: ; =
--tw-sepia: ; --tw-drop-shadow: ; --tw-backdrop-blur: ; =
--tw-backdrop-brightness: ; --tw-backdrop-contrast: ; =
--tw-backdrop-grayscale: ; --tw-backdrop-hue-rotate: ; =
--tw-backdrop-invert: ; --tw-backdrop-opacity: ; --tw-backdrop-saturate: =
; --tw-backdrop-sepia: ; --tw-contain-size: ; --tw-contain-layout: ; =
--tw-contain-paint: ; --tw-contain-style: ; margin-top: 1.25em; =
margin-bottom: 1.25em;">DATA Filtering:</strong> DKIM, ADSP, ATPS, =
DMARC, ARC, =E2=80=9CSpam Words=E2=80=9D =E2=80=9CSpam Assassin=E2=80=9D =
filtering possibilities</li></ul><p style=3D"font-size: 16px; =
white-space: pre-wrap; border: 0px solid rgb(227, 227, 227); box-sizing: =
border-box; margin: 1.25em 0px; color: rgb(13, 13, 13); font-family: =
ui-sans-serif, -apple-system, system-ui, &quot;Segoe UI&quot;, Roboto, =
Ubuntu, Cantarell, &quot;Noto Sans&quot;, sans-serif, Helvetica, =
&quot;Apple Color Emoji&quot;, Arial, &quot;Segoe UI Emoji&quot;, =
&quot;Segoe UI Symbol&quot;; font-variant-ligatures: normal; orphans: 2; =
widows: 2; background-color: rgb(255, 255, 255); =
text-decoration-thickness: initial; text-decoration-style: initial; =
text-decoration-color: initial;">(What is your current SMTP session =
residence time?  .5ms?  1-3 or more secs?)</p><p style=3D"font-size: =
16px; white-space: pre-wrap; border: 0px solid rgb(227, 227, 227); =
box-sizing: border-box; margin: 1.25em 0px; color: rgb(13, 13, 13); =
font-family: ui-sans-serif, -apple-system, system-ui, &quot;Segoe =
UI&quot;, Roboto, Ubuntu, Cantarell, &quot;Noto Sans&quot;, sans-serif, =
Helvetica, &quot;Apple Color Emoji&quot;, Arial, &quot;Segoe UI =
Emoji&quot;, &quot;Segoe UI Symbol&quot;; font-variant-ligatures: =
normal; orphans: 2; widows: 2; background-color: rgb(255, 255, 255); =
text-decoration-thickness: initial; text-decoration-style: initial; =
text-decoration-color: initial;">The Return Path is checked in many =
ways, with the most successful being CBV (Call Back Verifier). Despite =
its controversy, it remains effective. However, we still need to address =
the issue of compliant bad actors. Even if a sender adheres to all rules =
from SPF to DMARC, anonymous names can still pose a problem.</p><p =
style=3D"font-size: 16px; white-space: pre-wrap; border: 0px solid =
rgb(227, 227, 227); box-sizing: border-box; margin: 1.25em 0px; color: =
rgb(13, 13, 13); font-family: ui-sans-serif, -apple-system, system-ui, =
&quot;Segoe UI&quot;, Roboto, Ubuntu, Cantarell, &quot;Noto Sans&quot;, =
sans-serif, Helvetica, &quot;Apple Color Emoji&quot;, Arial, &quot;Segoe =
UI Emoji&quot;, &quot;Segoe UI Symbol&quot;; font-variant-ligatures: =
normal; orphans: 2; widows: 2; background-color: rgb(255, 255, 255); =
text-decoration-thickness: initial; text-decoration-style: initial; =
text-decoration-color: initial;">All the best,
Hector Santos</p></div></div></div></div></body></html>=

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