1 Topic by kinneyscott5

  • kinneyscott5
  • Member
  • Offline
  • Registered: 2016-10-30
  • Posts: 54

Topic: setting limits

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Hello

i know that this is probably off-topic but this is the only place that i know that could help me , so i have setted up iredmail and i'm using it as a mail checker (verifying if an email exist or not) using php , it was working great but lately i am getting an error when trying to verify multiple comcast at once:

421 resimta-po-09v.sys.comcast.net resimta-po-09v.sys.comcast.net Too many sessions opened
421 resimta-ch2-23v.sys.comcast.net resimta-ch2-23v.sys.comcast.net Too many sessions opened
All connection fails
kinneyscott@comcast.net
0

i looked over the error and it says

421 - [Too many sessions opened]     Comcast allows 25 simultaneous connections per sending IP address. This error results when that limit is exceeded.

is there a way to limit the amount of simultaneous connections ?

thanks

----

Spider Email Archiver: On-Premises, lightweight email archiving software developed by iRedMail team. Supports Amazon S3 compatible storage and custom branding.

2 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
  • iRedMail Developers
  • Offline
  • Registered: 2009-05-06
  • Posts: 31,094

Re: setting limits

is it IMAP protocol? if yes, try to increase value of "mail_max_userip_connectons" in /etc/dovecot/dovecot.conf.

3 Reply by kinneyscott5

  • kinneyscott5
  • Member
  • Offline
  • Registered: 2016-10-30
  • Posts: 54

Re: setting limits

Hello

no i'm using a php class that simulates sending an email and after reaching the RCPT:TO line it reads the result and abondons the sending email process

$this->_streamQuery("HELO " . self::parse_email($this->from));
        $this->_streamResponse();
        $this->_streamQuery("MAIL FROM: <{$this->from}>");
        $this->_streamResponse();
        $this->_streamQuery("RCPT TO: <{$email}>");
        $code = $this->_streamCode($this->_streamResponse());
        //$this->_streamResponse();
        $this->_streamQuery("RSET");
        //$this->_streamResponse();
        $this->_streamQuery("QUIT");

you can check the class here :

www.phpclasses.org/package/6650-PHP-Check-if-an-e-mail-is-valid-using-SMTP.html

4 Reply by craig

  • craig
  • Member
  • Offline
  • From: Canada
  • Registered: 2013-09-04
  • Posts: 272

Re: setting limits

kinneyscott5 wrote:

no i'm using a php class that simulates sending an email and after reaching the RCPT:TO line it reads the result and abondons the sending email process

If the class just abandons the connection that's not very polite, as the server you're checking is probably leaving the connection open and you're just making more connections and eventually hitting their limit.

5 Reply by kinneyscott5

  • kinneyscott5
  • Member
  • Offline
  • Registered: 2016-10-30
  • Posts: 54

Re: setting limits

craig wrote:
kinneyscott5 wrote:

no i'm using a php class that simulates sending an email and after reaching the RCPT:TO line it reads the result and abondons the sending email process

If the class just abandons the connection that's not very polite, as the server you're checking is probably leaving the connection open and you're just making more connections and eventually hitting their limit.

i think that exactly what it does , this is how it looks like on the logs

220 resimta-po-03v.sys.comcast.net resimta-po-03v.sys.comcast.net ESMTP server ready
Connection success mx1.comcast.net
HELO mydomain.com
250 resimta-po-03v.sys.comcast.net hello [2a02:c207:2019:2120::1], pleased to meet you
MAIL FROM: <kinneyscott@yahoo.com>
250 2.1.0 <kinneyscott@yahoo.com> sender ok
RCPT TO: <cherrysixteen@comcast.net>
250 2.1.5 <cherrysixteen@comcast.net> recipient ok
RSET
QUIT
0

it was working fine for about a year now and lately i've been experiencing some issues , it not just my server i purchased a new one and it gave the same issue

6 Reply by ZhangHuangbin

  • ZhangHuangbin
  • ZhangHuangbin
  • iRedMail Developers
  • Offline
  • Registered: 2009-05-06
  • Posts: 31,094

Re: setting limits

kinneyscott5 wrote:

421 - [Too many sessions opened]     Comcast allows 25 simultaneous connections per sending IP address. This error results when that limit is exceeded.

I just realize that this smtp server is "Comcast", not iRedMail?