May be related but I'm not sure. Fastmail seems like a well-known company and I think their servers would be on reputable sender lists. In that sense MXRoute was explicit about their insistence on keeping their servers trusted and that they would come down hard on users that would compromise their reputation.
When a message to Hotmail is delayed or blocked, I get an email from Fastmail containing details from Microsoft including the IP address of the offending server. When I look that address up in blocklists, the results are clean: No blocks amongst 60+ lists tested (depending on the service).
It feels like MS is checking the current SMTP address for my domain against the prior Rackspace address. It's as if it trusts the old server IPs and something needs to happen to have the new SMTP IP address(es) get trusted. But, none of the links that MS puts into its bounce messages say explicitly what to do. I've sent a lot of mail to Hotmail-having family in the past and they went through most of the time. Not perfect but close. One message even went through today after two got blocked.
I tried delisting the claimed offending IP address in the bounce message using an Office365 tool. Noticed in the confirmation message that Hotmail/Outlook.com delisting was handled through a separate link and have filed a ticket there.
When a message to Hotmail is delayed or blocked, I get an email from Fastmail containing details from Microsoft including the IP address of the offending server. When I look that address up in blocklists, the results are clean: No blocks amongst 60+ lists tested (depending on the service).
It feels like MS is checking the current SMTP address for my domain against the prior Rackspace address. It's as if it trusts the old server IPs and something needs to happen to have the new SMTP IP address(es) get trusted. But, none of the links that MS puts into its bounce messages say explicitly what to do. I've sent a lot of mail to Hotmail-having family in the past and they went through most of the time. Not perfect but close. One message even went through today after two got blocked.
I tried delisting the claimed offending IP address in the bounce message using an Office365 tool. Noticed in the confirmation message that Hotmail/Outlook.com delisting was handled through a separate link and have filed a ticket there.