Rate Limiting at btinternet for ControlEmail

7:30am Pacific — We have been seeing an increasing number of deferrals when attempting to deliver outbound mail to the btinternet.com servers.  We have made many attempts to contact responsible personnel at btinternet, but unfortunately they have been non-responsive thus far.  We are unaware of any unusual activity, mail flow, or other changes on our part that may have caused their mail system to begin rate-limiting our traffic.

Affected customers (mostly in the UK) may elect to use our North American infrastructure for their outbound relay, as that does not appear to be affected at present.  We are investigating the feasibility of diverting traffic destined for BT through alternative networks, although that may not be effective and ultimately the problem needs to be resolved at BT.  We are continuing our attempts to reach authoritative personnel at BT, and would encourage affected customers with relationships with BT to likewise contact their account managers to expedite resolution of the issue.