emails not being received from *.coop domain

[webstream]

Hello,
I am unable to receive emails from *.coop domain
ie. emails are not being received with any domain with more then 3 characters,
.coop .info .host

how to fix this and how to trouble shoot this ?

Please advise if any solution to this,

[Admin]

Hi,

There is no check we do for this. What is the error that you receive? Do you see an error in the SMTP activity/debug log of it rejecting the email sender?