3rd party email access
We have xfinity internet service via cable modem. We also have a webhosting account with a 3rd party provider, in this case bluehost. They also provide an email server for addresses related to our owned domain names, which we have used since the start with an email client, in this case Thunderbird. This has been the case for several years, with only sporatic email issues that are quickly resolved. Not so anymore, apparently.
We now have an issue where we are unable to access the 3rd party mailserver through an email client as it denies password authentication UNLESS we first trigger comcast to assign us a new IP (by changing the MAC address accessing the comcast network) which opens a window of about 60 minutes, give or take, where access is allowed with no difficulties whatsoever. When the window closes, must get a new IP address again before access can be regained. The remote mailserver responds to queries, it just denies any attempts at authentification once the time has expired.
Why contact comcast about this? Because we have found that the window for access that opens upon gaining a new IP closes regardless of whether or not we attempt to access the 3rd party mailserver. Nobody but comcast would know we have a new one, I would presume.
All connections, incoming and outgoing, are TLS/SSL with password. Have tried different email clients and had the same result. I see references here and there regarding comcast policy that only comcast mailservers will be allowed outgoing mail for comcast customers, but nothing I have seen is very diffinitive as to what xfinity/comcast customers can and cannot do regarding email. And even in the case where outgoing mail over comcast IPs is restricted to comcast servers only, it does not explain why even access to a non-comcast incoming mailserver would be blocked as well.
I look forward to any helpful response you might have.