Encountering 550 mailbox unavailable error with Route53 and Gmail

Other Questions Gmail
1

I’m facing a puzzling issue where I receive the message ‘550 5.1.1 Requested action not taken: mailbox unavailable’ when I try to email [email protected] from my Gmail. However, others can send emails to this same address without any hassle.

I had recently altered my MX records on Route53 and reverted them after accidentally deploying an old version of my code.

Here’s what my current MX record configuration looks like:

1 aspmx.l.google.com.
5 alt1.aspmx.l.google.com.
5 alt2.aspmx.l.google.com.
10 alt3.aspmx.l.google.com.
10 alt4.aspmx.l.google.com.

The TTL is 60 seconds.

For my SPF record, it’s as follows:
"v=spf1 include:_spf.google.com include:amazonses.com ~all"

The TTL for SPF is set to 3600 seconds.

Has anyone experienced a similar situation? I’m curious if it’s a problem with DNS settings or something else entirely.

2

This usually happens because Gmail aggressively caches DNS records and gets confused when you change MX records back and forth. Gmail’s servers probably cached some weird intermediate state and now they’re rejecting your emails.

I ran into the exact same thing during an email migration. Here’s what fixed it for me: temporarily change your MX record priority values (just bump them up or down a bit), wait 30 minutes, then set them back to Google Workspace’s standard priorities. This forces Gmail to dump its cache and grab fresh DNS data.

Also check if you’ve got DMARC policies running. Recent DNS changes plus strict DMARC can trigger these “mailbox unavailable” errors from Gmail while other email providers work fine.

3

This is a DNS propagation issue mixed with Gmail’s caching problems. Gmail is likely using outdated DNS information from your previous configuration even though you’ve changed the MX records back to their correct settings. The ‘550’ error indicates that Gmail cannot locate your mailbox, which means the emails are not reaching the appropriate mail servers.

I’ve encountered a similar situation when transitioning between mail providers. Although your TTL is set to 60 seconds, Gmail often caches DNS records for much longer than expected. You should utilize tools like dig or nslookup to verify that your nameservers are providing consistent answers. Additionally, consider the possibility that Gmail may have temporarily blacklisted your domain due to recent DNS alterations, which could explain why messages from other providers are going through without issue.

4

totally understand ur frustation! had this same issue before. make sure ur mx records r fully propagated, it might take some time. maybe try sending a test email after a bit. hang in there!