Hi Opalstack Team,
I just sent an email to a user whose email hosting is managed by Google, I'm guessing, and got the following error message:
Remote-MTA: dns; aspmx.l.google.com
Diagnostic-Code: smtp; 550-5.7.1 [220.127.116.11 12] Our system has
detected that this message is 550-5.7.1 likely unsolicited mail. To reduce
the amount of spam sent to Gmail, 550-5.7.1 this message has been blocked.
Please visit 550-5.7.1
https://support.google.com/mail/?p=UnsolicitedMessageError 550 5.7.1 for
more information. g63si4176238pgc.487 - gsmtp
Based on other forum posts, it seems like this is something you've deal with in the past by contacting the hosting companies. Is this a known issue with gmail at the moment?