Welcome, Guest Login

Support Centre

My ISP Blocks Port 25 - Is there an alternate port for cloud?

Last Updated: Jul 16, 2013 11:19AM BST


Some Internet Service Providers (ISPs) block SMTP port 25 outbound from their networks. This may affect your ability to use mkryptor cloud.


mkryptor cloud offers an alternate SMTP port of Port 587

Generally ISPs will not block port 587, so you should be able to use mkryptor cloud fine on this port. All other SMTP settings can remain the same, just change your outgoing port to 587.


The reason lots of ISPs block port 25 is because that port is often used by malware to send spam, without need for authentication. By blocking port 25 they protect themselves from this. Port 587 always requires authentication, making it no use to malware. So it is safe for the ISP to allow their customers to use this port.
seconds ago
a minute ago
minutes ago
an hour ago
hours ago
a day ago
days ago
Invalid characters found