btconnect.com smarthost not delivering all emails

[PaulSlaney]

I have a Microsoft Exchange (SBS 2010) system configured to use mail.btconnect.com as smarthost. We are a BT customer with a BT hosted domain.

Whilst most email is being delivered to recipients, not all of it is. Some is being returned with the error:

recipientaddress@recipientdomain.com
mail.btconnect.com #550 Recipient domain must exist ##

Yet the recipient address is perfectly valid.

Does anyone know why this may be happening?

[warriorfullight]

Same here. I tried a few test emails and even a few of it returned with an error. There is something that really need to get fixed.

[helpinghands]

I would check with the support helpdesk to see if your domain has been migrated to the Office 365 platform.

If it has, the new smarthost setting are as follows:

smtp.outlook.com

Port 587

SSL has to be enabled

[technoworld]

I have same error

#550 Recipient domain must exist ##

I use BT to relay the emails on exchange 2010

Need some help

[markp]

Hi technoworld,

I would contact the helpdesk with the examples of mail you have that is not being delivered, they might be able to run a mail trace to see where the issue lies.

Markp