Does anyone have contacts at Charter (Spectrum) and Cox? For some reason, our IP has been blocked by them and our customers are unable to send email via their charter/cox accounts. Thanks
Daniel Temple
VP of Operations
Pyranah Communications, LLC
828-743-2470 ext.205
Would you be talking about port 25/tcp outbound? Lots of ISPs will
block port 25 as a rule; you have to call to have it opened. At the
same time, you can request the PTR record you need to keep big mail
receivers happy.
If this is the case, that your customers cannot use your mail servers to relay mail then provide port 587/TCP (SUBMISSION) or even 465/TCP (SMTPS, deprecated).
If you mean that your mail servers can't send mail to Charter and Cox addresses, then indeed you need to find out what happened, fix it then request removal from their (and other) blacklists for which contacts there would be helpful (I am not one).
/mark