Hi,
Our application has been running happily for years but suddenly started getting the below errors:
class javax.mail.SendFailedException: 553-you are trying to use me [server-4.tower-245.messagelabs.com] as a relay, but I have not been configured to let
553-you [52.166.60.166, unknown] do this. Please visit
553-www.symanteccloud.com/troubleshooting for more details
553-about this error message and instructions to resolve
553 this issue. (#5.7.1)
The SMTP server is configured as cluster5.eu.messagelabs.com
This is affected a few different applications and no changes have been made at this end
The IP address we are sending from are (The reputations appear to be OK):
52.166.60.166
104.40.180.26
40.91.195.181
Please can you let me know what is causing this (Unofrtunately I cant find the login details to our messagelabs account either so cant check at that end)
Thanks