If when sending an email you are receiving this response, it means that the message could not be delivered to the recipient because it was classified as "Spam".
Why am I getting this error?
In the battle against spam, mail servers have implemented mass message detection procedures on all emails before they leave the servers. Each email is evaluated and scored according to spam rules to determine the likelihood that a real threat exists. Those that fail the test are returned to the sender with a 550 error message. This message is classified as spam and cannot be delivered.
Why does this occur in outgoing email messages?
Although email servers review all incoming email and evaluate it against their own filters, we also make the practice of detecting problems in outgoing email to help preserve the IP address reputation of our servers so that we prevent fall into a blacklist and you can no longer send any messages.
Evaluate the content of the email message you sent
Our servers evaluate whether the messages you are sending have patterns that equate them to a promotional message or spam. It is likely that if the subject or content of the message contains special characters, words or terms typical of spam email, it will be blocked before going to the recipient, returning error 550.
