I use phpmail on Linux VPS with sendmail. I hear from recipients who get duplicates from time to time. It also happened to me in the past. I finally captured the headers from a recipient today.
It appears that my ISP's MTA was sending the duplicates (i hope i read the headers correctly).
Here are what I see in the two headers. Any help is greatly appreciated!
#### 2 ### MTA sent it out at first time 2013 12:12:06 -0800 (12:12:06 Pacific)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1106.mail.bf1.yahoo.com with SMTP; Thu, 05 Dec 2013 12:12:06 -0800
### 2 ### MTA sent it out again at 2013 20:14:20 +0000 (12:14:20 Pacific, **2 min later!)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1531.mail.gq1.yahoo.com with SMTP; Thu, 05 Dec 2013 20:14:20 +0000
The entire headers are below:
======= 1st duplicated email header:
From r***@gmail.com Thu Dec 5 12:11:56 2013
X-Apparently-To: lxxx@yahoo.com via 98.138.90.182; Thu, 05 Dec 2013 12:12:09 -0800
Return-Path: <r***@gmail.com>
Received-SPF: permerror (encountered permanent error during SPF processing of domain of gmail.com)
X-Originating-IP: [208.109.80.198]
Authentication-Results: mta1106.mail.bf1.yahoo.com from=gmail.com; domainkeys=neutral (no sig); from=gmail.com; dkim=neutral (no sig)
#### 2 ### MTA sent it out at first time 2013 12:12:06 -0800 (12:12:06 Pacific)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1106.mail.bf1.yahoo.com with SMTP; Thu, 05 Dec 2013 12:12:06 -0800
#### 1 ### my host hand the msg to MTA
Received: from ip-xxx-63-186-24.ip.secureserver.net ([xx.63.186.24])
by p3plsmtps2ded04.prod.phx3.secureserver.net with : DED :
id xwC21m01B0Y0ede01wC2jp; Thu, 05 Dec 2013 13:12:02 -0700
x-originating-ip: xx.63.186.24
Received: (from apache@localhost)
by ip-xxx-63-186-24.ip.secureserver.net (8.13.8/8.13.8/Submit) id rB5KBuVZ003988;
Thu, 5 Dec 2013 13:11:56 -0700
Date: Thu, 5 Dec 2013 13:11:56 -0700
Message-Id: <201312052011.rB5KBuVZ003988@ip-xxx-63-186-24.ip.secureserver.net>
X-Authentication-Warning: ip-xxx-63-186-24.ip.secureserver.net: apache set sender to r***@gmail.com using -f
To: r***@gmail.com
Subject: =xxx
MIME-Version: 1.0
Content-Type: multipart/alternative;boundary="MIME_BOUNDRY"
From: <r***@gmail.com>
Reply-To: r***@gmail.com
X-Mailer: PHP5
X-Sender: r***@gmail.com
X-Priority: 3
Content-Length: 1542
===========2nd duplicated email header:
From r***@gmail.com Thu Dec 5 12:11:56 2013
X-Apparently-To: lxxx@yahoo.com via 98.138.91.217; Thu, 05 Dec 2013 20:14:26 +0000
Return-Path: <r***@gmail.com>
Received-SPF: softfail (transitioning domain of gmail.com does not designate 208.109.80.198 as permitted sender)
X-Originating-IP: [208.109.80.198]
Authentication-Results: mta1531.mail.gq1.yahoo.com from=gmail.com; domainkeys=neutral (no sig); from=gmail.com; dkim=neutral (no sig)
### 2 ### MTA sent it out again at 2013 20:14:20 +0000 (12:14:20 Pacific, **2 min later!)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1531.mail.gq1.yahoo.com with SMTP; Thu, 05 Dec 2013 20:14:20 +0000
### 1 ### my host hand the msg to MTA
Received: from ip-xxx-63-186-24.ip.secureserver.net ([xx.63.186.24])
by p3plsmtps2ded04.prod.phx3.secureserver.net with : DED :
id xwC21m01B0Y0ede01wC2jp; Thu, 05 Dec 2013 13:12:02 -0700
x-originating-ip: xx.63.186.24
Received: (from apache@localhost)
by ip-xxx-63-186-24.ip.secureserver.net (8.13.8/8.13.8/Submit) id rB5KBuVZ003988;
Thu, 5 Dec 2013 13:11:56 -0700
Date: Thu, 5 Dec 2013 13:11:56 -0700
Message-Id: <201312052011.rB5KBuVZ003988@ip-xxx-63-186-24.ip.secureserver.net>
X-Authentication-Warning: ip-xxx-63-186-24.ip.secureserver.net: apache set sender to r***@gmail.com using -f
To: r***@gmail.com
Subject: =xxx
MIME-Version: 1.0
Content-Type: multipart/alternative;boundary="MIME_BOUNDRY"
From: <r***@gmail.com>
Reply-To: r***@gmail.com
X-Mailer: PHP5
X-Sender: r***@gmail.com
X-Priority: 3
Content-Length: 1542
It appears that my ISP's MTA was sending the duplicates (i hope i read the headers correctly).
Here are what I see in the two headers. Any help is greatly appreciated!
#### 2 ### MTA sent it out at first time 2013 12:12:06 -0800 (12:12:06 Pacific)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1106.mail.bf1.yahoo.com with SMTP; Thu, 05 Dec 2013 12:12:06 -0800
### 2 ### MTA sent it out again at 2013 20:14:20 +0000 (12:14:20 Pacific, **2 min later!)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1531.mail.gq1.yahoo.com with SMTP; Thu, 05 Dec 2013 20:14:20 +0000
The entire headers are below:
======= 1st duplicated email header:
From r***@gmail.com Thu Dec 5 12:11:56 2013
X-Apparently-To: lxxx@yahoo.com via 98.138.90.182; Thu, 05 Dec 2013 12:12:09 -0800
Return-Path: <r***@gmail.com>
Received-SPF: permerror (encountered permanent error during SPF processing of domain of gmail.com)
X-Originating-IP: [208.109.80.198]
Authentication-Results: mta1106.mail.bf1.yahoo.com from=gmail.com; domainkeys=neutral (no sig); from=gmail.com; dkim=neutral (no sig)
#### 2 ### MTA sent it out at first time 2013 12:12:06 -0800 (12:12:06 Pacific)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1106.mail.bf1.yahoo.com with SMTP; Thu, 05 Dec 2013 12:12:06 -0800
#### 1 ### my host hand the msg to MTA
Received: from ip-xxx-63-186-24.ip.secureserver.net ([xx.63.186.24])
by p3plsmtps2ded04.prod.phx3.secureserver.net with : DED :
id xwC21m01B0Y0ede01wC2jp; Thu, 05 Dec 2013 13:12:02 -0700
x-originating-ip: xx.63.186.24
Received: (from apache@localhost)
by ip-xxx-63-186-24.ip.secureserver.net (8.13.8/8.13.8/Submit) id rB5KBuVZ003988;
Thu, 5 Dec 2013 13:11:56 -0700
Date: Thu, 5 Dec 2013 13:11:56 -0700
Message-Id: <201312052011.rB5KBuVZ003988@ip-xxx-63-186-24.ip.secureserver.net>
X-Authentication-Warning: ip-xxx-63-186-24.ip.secureserver.net: apache set sender to r***@gmail.com using -f
To: r***@gmail.com
Subject: =xxx
MIME-Version: 1.0
Content-Type: multipart/alternative;boundary="MIME_BOUNDRY"
From: <r***@gmail.com>
Reply-To: r***@gmail.com
X-Mailer: PHP5
X-Sender: r***@gmail.com
X-Priority: 3
Content-Length: 1542
===========2nd duplicated email header:
From r***@gmail.com Thu Dec 5 12:11:56 2013
X-Apparently-To: lxxx@yahoo.com via 98.138.91.217; Thu, 05 Dec 2013 20:14:26 +0000
Return-Path: <r***@gmail.com>
Received-SPF: softfail (transitioning domain of gmail.com does not designate 208.109.80.198 as permitted sender)
X-Originating-IP: [208.109.80.198]
Authentication-Results: mta1531.mail.gq1.yahoo.com from=gmail.com; domainkeys=neutral (no sig); from=gmail.com; dkim=neutral (no sig)
### 2 ### MTA sent it out again at 2013 20:14:20 +0000 (12:14:20 Pacific, **2 min later!)
Received: from 127.0.0.1 (EHLO p3plsmtps2ded04.prod.phx3.secureserver.net) (208.109.80.198)
by mta1531.mail.gq1.yahoo.com with SMTP; Thu, 05 Dec 2013 20:14:20 +0000
### 1 ### my host hand the msg to MTA
Received: from ip-xxx-63-186-24.ip.secureserver.net ([xx.63.186.24])
by p3plsmtps2ded04.prod.phx3.secureserver.net with : DED :
id xwC21m01B0Y0ede01wC2jp; Thu, 05 Dec 2013 13:12:02 -0700
x-originating-ip: xx.63.186.24
Received: (from apache@localhost)
by ip-xxx-63-186-24.ip.secureserver.net (8.13.8/8.13.8/Submit) id rB5KBuVZ003988;
Thu, 5 Dec 2013 13:11:56 -0700
Date: Thu, 5 Dec 2013 13:11:56 -0700
Message-Id: <201312052011.rB5KBuVZ003988@ip-xxx-63-186-24.ip.secureserver.net>
X-Authentication-Warning: ip-xxx-63-186-24.ip.secureserver.net: apache set sender to r***@gmail.com using -f
To: r***@gmail.com
Subject: =xxx
MIME-Version: 1.0
Content-Type: multipart/alternative;boundary="MIME_BOUNDRY"
From: <r***@gmail.com>
Reply-To: r***@gmail.com
X-Mailer: PHP5
X-Sender: r***@gmail.com
X-Priority: 3
Content-Length: 1542