450 4.4.1 Connection Time Out
Messages Queued on Delivery queue showing Error: 450 4.4.1 [internal] Connection Time Out
The following technical requirements apply to the delivery of electronic mail by the SMTP protocol to servers of Terra Networks Brazil S / A, for any equipment, hereinafter referred to as the Source Server. TERRA reserves the right to refuse or penalize access to e-mail system to "terra.com.br", at any time and without notice, on its own initiative or at the request of one third, those servers that fail From any of these conditions. http://www.terra.com.br/postmaster/ Source domain out of Terra.com.br requirements: RFC 1912, section 2.1. RFC 2821 RFC 2142 Must be included on: SPF - Sender Policy Framework SRS - Sender Rewriting Scheme
The Source Server must be authorized in the SPF record, if there is one of the areas used by their senders. Messages that fail the test of the SPF will be rejected. For messages automatically redirected, the Source Server must "take responsibility" for the messages redirected by him. This should be done through some mechanism rewrite sender (SRS - Sender Rewriting Scheme).