Getting error message trying to post in forum, posting doesn't succeed

[LogicalCreative]

I am getting the following error message when I try to post in the forum (in the "General Support -> Day-to-Day Use -> Start new topic" area):

"Ran into problems sending Mail. Error: 535 5.7.8 https://support.google.com/mail/?p=BadCredentials c24sm7151477pjs.51 - gsmtp"

What is going on with this? It happens both on MacOS Catalina with Chrome and Safari, and also on iOS with Chrome, that I have tried so far.

[LogicalCreative]

The above worked using MacOS Catalina with Firefox, by the way.

[LogicalCreative]

Re-attempting to post again in the "General Support -> Day-to-Day Use -> Start new topic" area using MacOS Catalina with Firefox produced the following error just now:

"Ran into problems sending Mail. Error: 535 5.7.8 https://support.google.com/mail/?p=BadCredentials v1sm6918468pjs.36 - gsmtp"

Not sure what the problem is. Does the forum work by sending mail somewhere?

[SteveInWA]

This forum runs on an ancient version Simple Machines SMF, and it is full of bugs.  Aside from that, their echo test number is down today.  So, it's not you - it's the forum software.

The fact that you ARE now able to post is a good sign; just ignore the errors.