What does " 5.7.1 Non-Compliant sender address. Code : -1." mean. I can't find a description.
Working at the office connected to wifi and was sending email with no problems. Came home and connected to wifi and getting the error message " 5.7.1 Non-Compliant sender address. Code : -1.". I was sending emails last night without a problem from home, so nothing should have changed for any of these locals.
All Replies (1)
make sure you are on the wifi network you think you are.
The error message is from a mail server, not Thunderbird. This information from Symantec might help https://support.symantec.com/us/en/article.TECH169847.html