I'm facing some email delivery problems and am hoping to get some insights here. Recently, I tried to send an email to my bank from my Microsoft 365 custom domain, but it bounced back. I then switched to my Gmail account, and that bounced as well with the error message: >>>503 #5.5.1 RCPT first.
I suspect it might be related to previous alias spamming we've experienced, which affected our reputation score, but I'm confused because these were sent from two completely separate servers and different email addresses. I tried using ChatGPT for help, but it kept suggesting solutions based on my end, even though the receiving server is the one bouncing back the emails.
I would appreciate any advice on this, and if there's a more suitable forum for this issue, please let me know!
1 Answer
Have you made sure that your DMARC, DKIM, and SPF records are set up correctly? Those settings can heavily influence your email deliverability. If something's misconfigured, it could lead to those kinds of bounce messages, especially from a custom domain.
That might be contributing to the issue with my Microsoft 365 account. But I'm really confused about why emails sent directly from my Gmail account are also getting bounced. It seems like two separate problems.