Some domains are not accepting emails from our server. The deliver failure error is 4.4.7 with this message: Could not deliver the message in the time limit specified. Please retry or contact your administrator.
When I run a dns report there are two errors:
ERROR: One or more of the nameservers listed at the parent servers are not listed as NS records at your nameservers. The problem NS records are:
Your domain does not have an SPF record. This means that spammers can easily send out E-mail that looks like it came from your domain, which can make your domain look bad (if the recipient thinks you really sent it), and can cost you money (when people complain to you, rather than the spammer). You may want to add an SPF record ASAP, as 01 Oct 2004 was the target date for domains to have SPF records in place (Hotmail, for example, started checking SPF records on 01 Oct 2004).
Are these the likely cause and, if so, are they something that can be fixed from our end? If not where to go from here?