Port 25 blocking

[koster]

Do all ISPs block port 25 for outgoing email via another service provider's outgoing email server?

[j2buttonsw]

That is an interesting question. Port 25 is not completely blocked as one can send mail via smtp. However, I have found that I can only send mail if it is going to my isp's email server. ie, I cannot send mail to mail.freeserve.com as I am with ntlworld. I guess they restrict smtp traffic to some IP addresses. So, I would say, yes they probably do.

[OBonio]

No. Freeserve do (all outgoing connections to port 25 get forwarded to the freeserve SMTP server from what I remember). I'm with virgin now, and they don't seem to 'block' it. For security reasons, I think Freeserve's heart is in the right place. But it's a pain when you're running your own SMTP server....