Gmail Delivery delayed Remote Server returned: ‘421 4.7.0

biddleUncategorizedLeave a Comment

In July 2021 messages I sent to started being returned. It took a little troubleshooting but I realized my signature was causing the problem. Apparently, Google has started blocking all emails that use short links. I removed “Twitter: LinkedIn:” from my signature and immediately messages were delivered without any problems.

I’m not sure if this has been reported yet, but I hope this helps someone out there with the same issue! I first noticed Google was blocking links on 7/10/2021.

Delivery has been delayed to these recipients:


Subject: Test Message 3

Remote Server returned: ‘421 4.7.0 [ 15] Our system has detected that this message is 4.7.0 suspicious due to the nature of the content and/or the links within. 4.7.0 To best protect our users from spam, the message has been blocked. 4.7.0 Please visit 4.7.0 for more information. bl28si2552811qkb.351 – gsmtp’