Hello there!
I'm testing FastMail with my custom domain. I have configured correctly the DNS settings and under the tab "Domains" everything is green checked. I have bought the domain using NameCheap.
Using the Fastmail web application (to exclude client configuration error) I can only receive the e-mail but If I send one the receiving does not receive anything not even in the spam folder.
In summary:
From other providers to FastMail everything is OK
From FastMail to other providers the outgoing mail is not delivered or sometimes the emails are delivered
after hours...
I have noticed that the problem is when the emails pass by new3-smtp.messagingengine.com.
Have you got any suggestions?
Let me know!
Thanks