2 of my customers have had intermittant problems sending emails to my domain. Customer 1 had the problem for several months. It was working fine before the problem occured. The problem then went away a couple of months ago. I never found the root of the problem.
Now another customer cant send me emails. They get a Error 550 verification failed. When trying to email me.
I have looed at other similar posts on EE, but have been unable to get to the bottom of my problem.