E.email blocked when multiple gmail recipients
Here is my issue : Everytime I try to create or reply to an email with a lot of recipients (from 10 to 60), all my emails from my @e.email address sent to @gmail.com mailboxes (sometime also @free.fr and @yahoo.fr) are blocked and I receive a non-delivery message error with this code : Diagnostic-Code: smtp; 550-5.7.1 [18.104.22.168 11] Our system has detected that this message is 550-5.7.1 not RFC 5322 compliant: 550-5.7.1 ‘From’ header is missing. 550-5.7.1 To reduce the amount of spam sent to Gmail, this message has been 550-5.7.1 blocked. Please visit 550-5.7.1 https://support.google.com/mail/?p=RfcMessageNonCompliant 550 5.7.1 and review RFC 5322 specifications for more information. r6si12659647wmf.104 - gsmtp
Of course the link doesn’t help at all because there is a From header, it’s my address @e.email, at least I guess. The delivery message tell me to send an email to the postmaster but is there really a postmaster to contact ?
Is there any way to fix this or a workaround ? If I can’t even send emails to multiple recipients I will have to back to my gmail account and I’d rather not !!