For few days we have been receiving complaints from many of our subscribed clients that they are not getting daily alert mails. We checked in our logs that the mails are accepted by the servers (MX record:
example.com.mail.protection.outlook.com), but all clients subscribed to this service are not getting our mails in their inbox. Mails are accepted without any fault by the client mail server.
Following is the log from our sendmail server. Note: we have valid SPF records. Also, our mail server is not blacklisted anywhere. Mail contains HTML embedded info about our services for which the client is subscribed.
to=<firstname.lastname@example.org>, delay=00:00:08, xdelay=00:00:08, mailer=esmtp, pri=206583, relay=xxxxx-co-za.mail.p...ction.outlook.com. [xxx.xxx.154.23], dsn=2.0.0, stat=Sent (<VPOP31.4.0e.20140910113951.917.f85.2.34364a7d@CMS1> [InternalId=58007828300753, Hostname=xxxxxxx.eurprd03.prod.outlook.com] Queued mail for delivery)
What should we do to work around this problem?