+ Post New Thread
Page 1 of 2 12 LastLast
Results 1 to 15 of 30
Internet Related/Filtering/Firewall Thread, port 25 blocked.. what are my options in Technical; The place Im at just now, the ISP blocks port 25 Outgoing(!) which makes using my smtp mail accounts impossible. ...
  1. #1

    RabbieBurns's Avatar
    Join Date
    Apr 2008
    Location
    Sydney
    Posts
    5,532
    Thank Post
    1,341
    Thanked 470 Times in 307 Posts
    Blog Entries
    6
    Rep Power
    200

    port 25 blocked.. what are my options

    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?

  2. #2

    Join Date
    May 2009
    Location
    England
    Posts
    264
    Thank Post
    58
    Thanked 36 Times in 35 Posts
    Rep Power
    20
    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...

  3. #3


    Join Date
    Feb 2007
    Location
    Northamptonshire
    Posts
    4,706
    Thank Post
    354
    Thanked 807 Times in 722 Posts
    Rep Power
    348
    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.

  4. Thanks to kmount from:

    RabbieBurns (22nd September 2009)

  5. #4

    RabbieBurns's Avatar
    Join Date
    Apr 2008
    Location
    Sydney
    Posts
    5,532
    Thank Post
    1,341
    Thanked 470 Times in 307 Posts
    Blog Entries
    6
    Rep Power
    200
    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...)

  6. #5

    RabbieBurns's Avatar
    Join Date
    Apr 2008
    Location
    Sydney
    Posts
    5,532
    Thank Post
    1,341
    Thanked 470 Times in 307 Posts
    Blog Entries
    6
    Rep Power
    200
    ah sweet. that works without authentication. thanks

  7. #6

    Michael's Avatar
    Join Date
    Dec 2005
    Location
    Birmingham
    Posts
    9,345
    Thank Post
    242
    Thanked 1,602 Times in 1,278 Posts
    Rep Power
    346
    Hmm why would any ISP want to block port 25? Seems a strange decision to me.

  8. #7

    RabbieBurns's Avatar
    Join Date
    Apr 2008
    Location
    Sydney
    Posts
    5,532
    Thank Post
    1,341
    Thanked 470 Times in 307 Posts
    Blog Entries
    6
    Rep Power
    200
    Quote Originally Posted by Michael View Post
    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.

  9. #8
    Fuzzz's Avatar
    Join Date
    Nov 2008
    Location
    Netherlands
    Posts
    120
    Thank Post
    57
    Thanked 10 Times in 9 Posts
    Rep Power
    14
    Quote Originally Posted by Michael View Post
    Hmm why would any ISP want to block port 25? Seems a strange decision to me.
    It stops malware from sending spam.

  10. #9

    Michael's Avatar
    Join Date
    Dec 2005
    Location
    Birmingham
    Posts
    9,345
    Thank Post
    242
    Thanked 1,602 Times in 1,278 Posts
    Rep Power
    346
    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

  11. #10
    Fuzzz's Avatar
    Join Date
    Nov 2008
    Location
    Netherlands
    Posts
    120
    Thank Post
    57
    Thanked 10 Times in 9 Posts
    Rep Power
    14
    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.

  12. #11


    Join Date
    Feb 2007
    Location
    Northamptonshire
    Posts
    4,706
    Thank Post
    354
    Thanked 807 Times in 722 Posts
    Rep Power
    348
    Quote Originally Posted by Michael View Post
    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.

  13. #12

    powdarrmonkey's Avatar
    Join Date
    Feb 2008
    Location
    Alcester, Warwickshire
    Posts
    4,867
    Thank Post
    412
    Thanked 778 Times in 651 Posts
    Rep Power
    182
    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.

    Quote Originally Posted by Potato-Peeler
    Failing that the South Africans recently tested carrier pigeons vs E-mail...
    No, they didn't.

  14. #13

    powdarrmonkey's Avatar
    Join Date
    Feb 2008
    Location
    Alcester, Warwickshire
    Posts
    4,867
    Thank Post
    412
    Thanked 778 Times in 651 Posts
    Rep Power
    182
    Quote Originally Posted by RabbieBurns View Post
    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

  15. #14

    Michael's Avatar
    Join Date
    Dec 2005
    Location
    Birmingham
    Posts
    9,345
    Thank Post
    242
    Thanked 1,602 Times in 1,278 Posts
    Rep Power
    346
    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.

  16. #15
    SC-UK's Avatar
    Join Date
    Feb 2009
    Location
    London
    Posts
    569
    Thank Post
    36
    Thanked 85 Times in 71 Posts
    Rep Power
    30
    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



SHARE:
+ Post New Thread
Page 1 of 2 12 LastLast

Similar Threads

  1. [CLOSED] Bug/Error: Ads Blocked
    By kmount in forum EduGeek.net Site Problems
    Replies: 26
    Last Post: 16th May 2009, 05:57 PM
  2. does this need to be blocked??
    By mikeymike in forum General Chat
    Replies: 20
    Last Post: 20th October 2008, 08:51 PM
  3. Ad Blocked
    By witch in forum General Chat
    Replies: 5
    Last Post: 15th July 2008, 06:15 PM
  4. Replies: 3
    Last Post: 19th February 2008, 11:13 PM
  5. [CLOSED] Misc: chat blocked
    By localzuk in forum EduGeek.net Site Problems
    Replies: 3
    Last Post: 7th January 2008, 12:36 PM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •