I get an error message when I send an email.

Error message when sending email

Here you can find a list of error messages and solutions when sending emails:

552 5.2.0 automated process detected unsolicited content

Problem: The recipient has rejected your email because the recipient does not like the content of your email. The exact reason can be provided by the recipient’s provider.
Solution: Change your email text until you are able to send the email. Remove all hyperlinks.