Email security smtp port

Good day,

As we know, secure email cloud is connected or communicating to the mailbox via smtp port 25 (please correct me if im wrong) and also the email traffic. Would there be a way to change the smtp port or the inbound and outbound IP that was configured on the email secure.cloud? If yes, is there any article, white paper or admin guide that is availble? Any feedback is much appreciated, i just need answer badly. Thanks