port 25 blocked.. what are my options

[RabbieBurns]

The place Im at just now, the ISP blocks port 25 Outgoing(!) which makes using my smtp mail accounts impossible. I can connect to my vpn back home and send mail that way, but it slows down the browsing and downloads obviously..

Options I can think of are to run a smtp server on a different port on one of my servers back home..

Or a socks5 or something maybe and just setting it to go through that to send - would that work?

[Potato-Peeler]

Could you not contact the ISP in an attempt to get the port unblocked?
Failing that the South Africans recently tested carrier pigeons vs E-mail...

[kmount]

Chances are if they're blocking it you will be able to use their provided one on port25.

Or yes, you could enable smtp on an alternate port.

[RabbieBurns]

im just renting a room in the place only got the wireless password dont have any info or the account or account login details to use the isp smtp (unless it might work with no auth? worth a try...)

[RabbieBurns]

ah sweet. that works without authentication. thanks

[Michael]

Hmm why would any ISP want to block port 25? Seems a strange decision to me.

[RabbieBurns]

Hmm why would any ISP want to block port 25? Seems a strange decision to me.

I could see why them blocking it incomoing to stop you running your own mail server etc.. but yeh, outgoing is daft.

But using their one works. I should have tried it before tbh, I just assumed it would require login details.

[Fuzzz]

Hmm why would any ISP want to block port 25? Seems a strange decision to me.

It stops malware from sending spam.

[Michael]

But you can just change the port your application uses from 25 to something else. It's like ISPs trying to prevent users using bittorrent... you can change it to any random port. You don't actually gain anything blocking port 25 is what I'm trying to say

[Fuzzz]

It's the port 25 on the receiving side. If I want to send e-mail to, for example, hotmail.com, I have to send it to their mailserver on port 25.

Many ISP's block port 25 so malware can't send spam. If you want to send e-mail via SMTP you have to do that via their mailserver.

[kmount]

But you can just change the port your application uses from 25 to something else. It's like ISPs trying to prevent users using bittorrent... you can change it to any random port. You don't actually gain anything blocking port 25 is what I'm trying to say

If I'm an ISP and I ONLY allow outbound SMTP access to my SMTP server I can control exactly what's going out so anybody infected with mailers etc will show up quickly.

Most malware uses a 'known' smtp server either a listed open relay, or the one configured on the users outbound mail client so it can't be tracked back to John Smith running his own spam mail server on port 12345.

I've yet to see an RBC allow direct outbound SMTP access to anywhere other than their own boxes for this reason.

[powdarrmonkey]

Unless you're doing something funky like SPF, I'd always try and use the local ISP's SMTP server - it's closer to you in networking terms as well as geographical.

Failing that the South Africans recently tested carrier pigeons vs E-mail...

No, they didn't.

[powdarrmonkey]

But using their one works. I should have tried it before tbh, I just assumed it would require login details.

Only if you're outside their network. If you're inside, they already know where you live

[Michael]

I suppose it does protect the ISP if they can control what goes out, but still there are clearly ways around this as spam is getting an increasingly bigger problem every year.

[SC-UK]

The best port to try is 586 if anybody has this problem in the future and needs to authenticate.

My ISP blocks all SMTP traffic apart from to it's own mail servers on port 25. Change it to 586 (another common SMTP port), and it works without a problem.

Tom