@ComcastCSAEmail (Comcast Support for Email),
My @comcast.net email address has suddenly not been able to receive incoming emails from a particular email address, my personal domain one that is being forwarded through from my Domain Name Host provider Pair Networks (pair.com). Since Friday (May 15, 2020) afternoon until now, essentially all emails from there are being blocked, and are not successfully being delivered through to my @comcast.net email inbox (which is how I have things configured). Everything had been working fine for years, in this configuration.
I've contacted Pair Networks, and they indicate that Comcast's email servers are blocking their virulha.pair.com (126.96.36.199), likely using a Real-Time Blocklist (RBL) by third-party service Vade Security called the Vade Threat List (VTL)? Perhaps this is related to some overall Domain Name Server Blocking (DNSB) thing, maybe Comcast Error Code "BL001000"? Can Comcast correct/override this on your end, so that my emails forwarded from Pair can come through to Comcast, again? Also, another one of their domains/IPs being blocked might be mailwash38.pair.com (188.8.131.52).
No changes have been made to any configurations within my Comcast Email webmail's settings, nor my desktop email client's software, nor to my mobile device's native email client settings, either. My @comcast.net email address' inbox.outbox work normally, otherwise. So, I know it's not on my receiving software's end; it's deeper within the Comcast email server level.
I could provide my exact email address being blocked, if that'd help (but the info above should suffice). And I do have an example of one bounced email that I could provide, which might have more specific metadata details, if you can tell me how how Private Message @ComcastCSAEmail off-Forum, or a Comcast Support emil address to use? However, it seems most emails are just getting dropped "into the void," and not returning bounced messages. Hopefully this info is sufficient to lift any blacklist being applied to messages coming through Pair Networks's email service / my own account at Comcast.
please refer the domain to http://postmaster.comcast.net/smtp-error-codes.php#BL001000