Re: Unable to send messages

> Date: Sunday, March 13, 2022 06:50:45 +0800
> From: Bret Busby <[email protected]>

> 
> The Network log from the earlier version of claws mail, which gives
> more detail in the Network log;
> 
> "
> * Account '[email protected]': Connecting to SMTP server:
> mail.bretbusby.net:25...
> [06:18:26] SMTP< 220-cp-43.webhostbox.net ESMTP Exim 4.94.2 #2 Sat,
> 12 Mar 2022 22:18:26 +0000
> [06:18:26] SMTP< 220-We do not authorize the use of this system to
> transport unsolicited,
> [06:18:26] SMTP< 220 and/or bulk e-mail.
> [06:18:26] SMTP> HELO bret-Aspire-V3-772-UbuntuMATE
> [06:18:26] SMTP< 250 cp-43.webhostbox.net Hello
> bret-Aspire-V3-772-UbuntuMATE [1.146.147.209]
> [06:18:26] SMTP> MAIL FROM:<[email protected]>
> [06:18:27] SMTP< 550 Access denied - Invalid HELO name (See RFC2821
> 4.1.1.1) ** error occurred on SMTP session
> *** Error occurred while sending the message:
> 550 Access denied - Invalid HELO name (See RFC2821 4.1.1.1)
> * Account '[email protected]': Connecting to SMTP server:
> mail.bretbusby.net:25...
> [06:24:23] SMTP< 220-cp-43.webhostbox.net ESMTP Exim 4.94.2 #2 Sat,
> 12 Mar 2022 22:24:23 +0000
> [06:24:23] SMTP< 220-We do not authorize the use of this system to
> transport unsolicited,
> [06:24:23] SMTP< 220 and/or bulk e-mail.
> [06:24:23] SMTP> HELO bret-Aspire-V3-772-UbuntuMATE
> [06:24:23] SMTP< 250 cp-43.webhostbox.net Hello
> bret-Aspire-V3-772-UbuntuMATE [1.146.147.209]
> [06:24:23] SMTP> MAIL FROM:<[email protected]>
> [06:24:24] SMTP< 550 Access denied - Invalid HELO name (See RFC2821
> 4.1.1.1) ** error occurred on SMTP session
> *** Error occurred while sending the message:
> 550 Access denied - Invalid HELO name (See RFC2821 4.1.1.1)
> * Account '[email protected]': Connecting to SMTP server:
> mail.bretbusby.net:465...
> *** Session timed out. You may be able to recover by increasing the
> timeout value in Preferences/Other/Miscellaneous.
> * Account '[email protected]': Connecting to SMTP server:
> mail.bretbusby.net:465...
> *** Session timed out. You may be able to recover by increasing the
> timeout value in Preferences/Other/Miscellaneous.
> "
> 
> The timeout period was changed from 60s to 180s, for the last
> instance.

Changing the timeout isn't going to help. You should be submitting
your mail from claws to either port 465 or 587, or ... if you insist
on using 25 (which isn't intended for client submission any longer)
you need to set the hostname properly on your machine, plus set up
forward and reverse DNS records for it.