@Townman wrote:
Port 2525 does not respond on either the old servers nor the Greenby service. I would not have expected it to, as 2525 is a substitute for 25 which ought never to be used in the first place for email message submissions.
@Townman - Thanks for checking that, as now we have a definitive answer that port 2525 isn't an option.
@Townman wrote:
... I grow weary of - port 587 is the ONLY approved port for email message submission.
It is impossible to provide absolute guidelines on these things as everything in the communication chain has to work.
For example, my daughter has had her own domain name and hosted email with IONOS since she was eleven years old. From initial setup her email SMTP used port 587 which worked perfectly at home, at two schools, various local clubs, sixth form college, multiple UK and foreign holidays, coffee shops, airports, travelling around Europe for a year, etc. However, on arriving at university "halls of residence" the campus network seemed to be blocking SMTP port 587, so she was forced to use SMTP port 465 for the year that she was living there.
So even when the approved port 587 between the email client and the email servers is correct and has been working for years, if the local internet connection has some sort of port filtering, then some experimentation might be needed.
