Is port 25 blocked for outgoing emails?
We have seen a significant increase in the amount of spammers using our VPS hosting to send unsolicited email. As a result of this, our subnets become blacklisted, making it very difficult for legit email to be sent out to the internet.
In order to mitigate this issue and protect our genuine customers, we have taken the decision to block port 25 for outbound emails.
The work around
We provide a smarthost (relay) SMTP service which our customers can use to send email through within our network, the emails are also checked and filtered which ensures the emails are clean when they are sent.
SPF Example: yourdomain.com IN TXT "v=spf1 a mx include:_spf.smtpcluster.cloud2b.net -all"
What if i need port 25 enabled on my VPS?
You can raise a ticket which will be reviewed by our compliance team. We would need justification or a business case as to the reasons for using port 25. A correctly configured server will use PTR records, any relays closed and will not be listed in any online spam blacklists.
If the justification is successfully approved then the port would be monitored and rate limited for a given period.