Most of you will already be aware that we have had to make changes recently to combat email deliverability problems. It can be difficult to determine what the exact cause of an issue is, sometimes its simply a user sending out unsolicitored emails from their account on the server (like newsletters that people havn't opted for and the recipient reports it), other times it can be a hack on a vulnerable joomla or wordpress site that is out of date.
We have been having major email deliverability problems recently with certain destinations. At this moment Microsoft is giving us a lot of trouble. Analyzing the data, it appears that they are probably blocking us because of the number of clients who are forwarding emails to hotmail.com, msn.com, outlook.com, etc. Incoming spam gets forwarded, Microsoft sees the content as spammy, and then suddenly they are refusing to accept any email from our servers.
So to put this simply, if you're recieving spam emails and your emails are actually not landing on our server but instead forwarding to another email client like hotmail, hotmail will think that our server sent that spam (because it forwarded it) even though it didnt.
Frankly, forwarding has become such an issue over the last few years that we'd love to just ban all forwarding completely. However, that's not feasible--even if we wanted to ban forwarding to destinations off server, people will still need to forward role-based emails (sales@, info@ for example) to actual users internally.
So, we have coded up a solution that will disallow the creation of forwarders to certain problem destination domains. This is being rolled out to all servers today. Then, very soon, probably within 24-48 hours, we will be deleting all existing forwarders destined to those domains.
Clients who are using forwarders to the problem destinations should change those forwarders to send somewhere else, if they are important. Otherwise, those forwarders will be completely removed and will stop working.
The current list of destination domains for forwarding which will be disallowed and removed are:
aol.com
comcast.net
cs.com
earthlink.net
hotmail.com
hotmail.co.uk
msn.com
outlook.com
prodigy.com
yahoo.com
yahoo.co.uk
This list may grow, and the above list will be updated as that happens. Originally gmail.com was going to be included, but it has been decided for this first implementation we'll leave gmail alone. They have been deferring emails from our servers quite a bit, but not outright rejecting. If this changes, we may have to add gmail. If we were to do that an email will be sent with advance notice.
Torsdag, Januar 8, 2015