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Change Webmail smtp port?

Discussion in 'E-mail Discussion' started by ksechrist, May 9, 2019.

  1. ksechrist

    ksechrist Active Member

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    I have a user who uses Horde exclusively, and he's complaining that email to charter.net bounces. I did some testing, and when I send an email from Horde, it shows in the log that it's using port 25, and it bounces. When I use my email client, it uses port 465 and the email is delivered to charter.

    So how do I make Horde (or all webmail) use port 465 exclusively to send email?
     
  2. LucasRolff

    LucasRolff Well-Known Member

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    It bounces with what message? charter.net should accept email on port 25 :) At least mx0.charter.net does.
     
  3. ksechrist

    ksechrist Active Member

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    thanks for the reply... turns out that my email on port 465 bounced as well, it just took longer (I found it stuck in the queue and didn't get the bounce until I forced delivery)

    Here's the bounce message:


    host mx0.charter.net [47.43.18.9]
    SMTP error from remote mail server after initial connection:
    554 impin013.msg.chrl.nc.charter.net cmsmtp ESMTP server not available AUP#I-1000

    I called Charter about this the other day and they said they're having trouble consolidating mail servers. I don't buy it. I feel like it's getting blocked, I'm just not sure why.

    I do have 5 dedicated IP addresses, and they're all clean, but I've read that charter will block huge IP blocks so now I'm worried that's what happened.
     
  4. sparek-3

    sparek-3 Well-Known Member

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    This is probably a case of companyA (Charter) blocking an IP simply because they can.

    But they will never tell you why they blocked the IP.

    This will have nothing to do with what port your users are connecting to on your server. SMTP to SMTP communication is always done on port 25. That's the standard port. Otherwise, mail communication would never work if each SMTP server around the world was able to accept messages on any port they deemed for themselves.
     
  5. ksechrist

    ksechrist Active Member

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    Thank you. I have come to the same conclusion - IP is blocked.
     
  6. cPanelLauren

    cPanelLauren Forums Analyst II Staff Member

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    It does indeed sound like it's blocked and I'm glad to see that you were able to identify the issue.
     
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  7. ksechrist

    ksechrist Active Member

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    Update, in case this helps someone else:

    I called Spectrum (Charter) again about this and they insisted that the problem was with my hosting company. I have a dedicated server and 5 clean IPs, but they weren't listening so I hung up and contacted my hosting provider.

    The hosting company checked my server and said it was good, and told me to contact Charter again.
    .
    So I decided to check IP addresses NEAR mine (I found a website that would check a range of IPs), and found a TON of them on Barracuda's RBL. My IPs weren't listed, but 37 others in my /24 block were. Armed with this info, I went back to the hosting company. They're looking into it. *sigh*
     
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  8. cPanelLauren

    cPanelLauren Forums Analyst II Staff Member

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    Well, I'm glad they're looking into it - thankfully barracuda drops blacklists pretty quickly pending the issue that got them blacklisted doesn't occur again.
     
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