We have email provided by BT, but using a different domain name.
Over the past few months we've been told more frequently by various clients that they have sent us emails which have bounced back, but when they've been sent again immediately afterwards they've come through to us.
One error was a 'Relaying denied' error, but this is not always the case (I'm afraid I haven't been sent examples of other error messages'. Our IT person suggests it could be a problem with the BT mail servers, and to call to find out if there have been any recent technical issues with their servers.
If anyone has experienced the same I'd appreciate an idea of where the problem may lie and how they fixed it as I'm 100% sure that if I call and ask if there are any problems on BT's end, the answer will always be 'no'. Even if there is a problem I feel the answer might be that there will always be intermittant issues which can't be foreseen/avoided.
First off I would go to MXtoolbox.com
Enter in your domain name (the bit after the @ in your email address).
Press enter and take a note of the results
If everything is correct then you should only have one MX record it will look like xxxxxxx.protection.outlook.com
so if your domain is Burkem5.com
then your mail record should be
burkem5.mail.protection.outlook.com (or something very similar).
If you have other records then these need to be deleted as more than likely they lead to a server which does not exist
such as ibmr.btconnect.com or ms123456.invalid
Removing these these should help alot.
I would also say that if your MX record is mail.eo.outlook.com call BT and ask for your protection record which is normally the same but mail.protection.outlook.com
Hope this helps