The domain you are sending from is not valid. Ensure the external mail server is up and running and accepting connections over port 25 (SMTP).ĥ04 5.5.2: Sender address rejected: need fully-qualified address

The message will be deferred to be resent at a later time. When your domain is Split Domain Routing enabled and the recipient’s address (hosted on the external mail server) soft fails. Try again later, or reduce the number of messages you're sending to this recipient.Ĥ.4.1: The recipient's server was temporarily unavailable to accept your message (G6) The receiving mail server is receiving too much mail. The sending IP has too many concurrent connections with our servers. Wait a few minutes, then try sending the message again.Ĥ21: Too many concurrent connections from this client (G2) The receiving mail server experienced an internal issue. Ask the recipient to Safelist/Whitelist your domain. The recipient’s server has received too much spam from this source.

Then verify the domain part of the email is correct.Ĥ51 4.3.0: Client host rejected: Throttled - Too much spam from your mail server. The recipient is unable to verify the existence of your domain.įirst, verify you have spelled the email address correctly. The recipient must create MX records with their DNS host so that they can receive email.Ĥ50 4.1.8: Sender address rejected: Domain not found There are no MX records for the recipient's domain From time to time you might send an email out and find you receive an email bounce back with an obscure message as the error in the message.īelow is a table of the possible messages, what they mean and a solution.

Server email bounce back message gmail