Hi Franck,

Looking at this link, the error is related to sending multiple mailfrom commands. Not sure whether this is the case on your site. Can you provide site admin access so I can reproduce the issue and investigate? Is there a test post you would like me to test comments on?

Hi,

I think I found the problem. In Joomla I sent mail with SMTP function, now I changed to PHP MAILER and the error message disappeared.

Hey Franck,

Thanks for the update and glad to know that PHP mailer works for you.

FYI, SMTP mail function should also work without error. But if you don't want to investigate further, it's fine too.