Can't send emails

Hello TBUDL'ers,

For the last two days my TB! has been unable to send emails. The error appearing
in the log is:

--------------------------- Edit Mail Message -> June Fletcher <[email protected]>
--------------------------- Server reports error. The response is: 5.1.0 <[email protected]> sender rejected
--------------------------- OK ---------------------------

I have tested several different email destinations and they all are refused with
the same above error message.

I have already checked with my ISP (Spectrum) and proved that at least from
their website I can send emails to the ones TB! rejected.

There does not appear to be a problem with receiving emails so I assume my email
password is the same as it always has been. However, out of curiosity, is it
possible to view the password in ACCOUNT PROPERTIES>TRANSPORT?

I had to go back to my ESP to send this email.

--
TIA,
Jack LaRosa

Using TB! 6.0.12
OS: Win 10 v6 Build: 9200

________________________________________________
Current version is 9.1.18 | 'Using TBUDL' information:
http://www.silverstones.com/thebat/TBUDLInfo.html