Q: How does LISTSERV archive its messages and how do I export them?

By Jacob Haller
Senior Support Engineer, L-Soft

Ever wondered how LISTSERV stores your list messages or how to export them for use elsewhere? This tech tip breaks down the archive file format and naming convention and provides practical guidance, examples and links to official documentation to help you understand and work with the archive format in LISTSERV.

Key Topics Covered

Where Archive Files Are Stored

Archive files are saved in the location defined in the list's "Notebook" setting.
File names follow a pattern like LISTNAME.LOGyymmw, indicating the year, month and week.

Exporting or Converting Archives

The LISTSERV archive format is simple but not widely supported by other tools.
You can convert files to formats like mbox using third-party tools.

Understanding the File Format

Messages are separated by lines of equal signs and include full headers.
HTML messages and attachments are stored in encoded form.
The format reflects how the message was received – not how it appeared in inboxes.

The Location and Name of the Archive Files

LISTSERV stores a mailing list's archives in the location given in the list's "Notebook" setting, in files with names like:

NAMEOFLIST.LOGyymmw

NAMEOFLIST is the name of the mailing list, and "yymmw" is the time period covered by this particular notebook file – "yy" is the two-digit year, "mm" the two-digit month, and "w" the week of the month ("a" for the 1st through the 7th, "'b" for the 8th through the 14th and so on). So, for instance, EXAMPLE.LOG2008C would contain messages distributed to the EXAMPLE mailing list during the third week of August 2020.

The above applies to mailing lists configured with "Notebook= Yes,..,Weekly,...". For mailing lists with monthly archives, the file name would only specify the year and month. For example, EXAMPLE.LOG2101 would contain messages from January 2021.

Different naming conventions are used for mailing lists with Single or Separate archive intervals configured. Details can be found in the List Keyword Reference document at:

https://www.lsoft.com/manuals/17.5/listkwd/kNotebook.html

Converting or Exporting Notebook Files

While the format LISTSERV uses is fairly simple, there are not any commonly used apps or tools (other than LISTSERV) that can be used to view them, so typically you will want to convert them to another format that is more widely supported, such as the Unix "mbox" format. We don't provide or support any tools to perform this sort of conversion, but if you perform a web search for "LISTSERV to mbox", you should find some third-party options. Once the files are in an mbox format, then a similar search should find tools to convert them to your preferred format (for example, "mbox to PDF" if you want to convert to a PDF format).

The Format of the Notebook Files: An Example

As described in Section 18.10.3 of the Site Manager's Manual, each message is preceded by a line of 73 equals signs. After that, any relevant headers from the message are included, followed by the message itself.

For plain-text messages, this looks pretty much the way you would expect it to (you can find some examples in the above-linked documentation). However, it will look much different if the message is more complicated. For instance, let's say that you sent a message with some HTML formatting and an embedded image:

This is a test message with an embedded image

Thanks!

As expected, the version in the notebook beings with the line of equals signs and is followed by the message headers:

========================================================================= Date: Thu, 22 May 2025 15:09:21 -0400 Reply-To: Example List <EXAMPLE@LISTSERV.EXAMPLE.COM> Sender: Example List <EXAMPLE@LISTSERV.EXAMPLE.COM> From: Jacob Haller <jacob@XXXXXX.NET> Subject: Test with image and HTML Content-Type: multipart/alternative; boundary="Apple-Mail=_C1EF28E8-56B4-4ECA-B066-089EB9168571" Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.600.51.1.1\)) Message-ID: <EXAMPLE%202505221509322140.0010@LISTSERV.EXAMPLE.COM>

What follows will differ significantly from the version of the message your subscribers saw in their inboxes, or from how the archives look in the LISTSERV web interface.

The reason is that email standards were originally designed to transmit plain text, with any attachments having to be encoded as text. That encoded version of the attachments is what you'll see in the notebook file, and, for HTML-encoded messages, you'll also see the raw HTML code rather than formatted text. The result can be a strange-looking and often unreadable mess, at least until it's decoded and displayed normally again.

Returning to the above example, let me draw your attention to this particular header:

Content-Type: multipart/alternative;

The multipart/alternative content type indicates that several versions of the message were included in the original message, in this case a plain-text version and an HTML version. Most subscribers would have only seen the HTML version.

In the body of the message, we therefore get a (slightly encoded) plain-text version of the message:

--Apple-Mail=_C1EF28E8-56B4-4ECA-B066-089EB9168571 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 This is a test message with an embedded image: =EF=BF=BC

This is then followed by the HTML version of the message:

--Apple-Mail=_C1EF28E8-56B4-4ECA-B066-089EB9168571 Content-Type: multipart/related; type="text/html"; boundary="Apple-Mail=_23E0C4A9-5D33-4C85-8425-0C8C1C96FB96" --Apple-Mail=_23E0C4A9-5D33-4C85-8425-0C8C1C96FB96 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii <html><head><meta http-equiv="content-type" content="text/html; charset=us-ascii"></head><body><p align="center">This is a <b>test</b> message with an <u>embedded image</u></p><br /><div align="center"><img src="cid:4BA3B651-99C2-4095-9AE0-E8C4BB11B2DF" alt="lsoft.png"></div><p align="center">Thanks!</p></body></html>

And this is followed by the encoded attachment containing the image that was included in the original message:

--Apple-Mail=_23E0C4A9-5D33-4C85-8425-0C8C1C96FB96 Content-Transfer-Encoding: base64 Content-Disposition: inline; filename=lsoft.png Content-Type: image/png; x-unix-mode=0644; name="lsoft.png" Content-Id: <4BA3B651-99C2-4095-9AE0-E8C4BB11B2DF> iVBORw0KGgoAAAANSUhEUgAAAGQAAABLCAYAAACGGCK3AAAACXBIWXMAAAsTAAALEwEAmpwYAAAJ 0ElEQVR4nOxbXWwUxx3/7+7tns/2YZNgklYJAkxIlFSt2oIUKZWgBaRGEDmtFPJGcWI7FnnoS6Ug 0T5VUKE+JyK2iZ0+pCqJVEWCNkoAkT40SNCX9qUhuE5CEmLnwzF2bN/tx3T/c7fn2dnd2d2z75hD +5MQ3r2ZnY/f/D9nRiGEQAZ5oN7uDmTwIyNEMmSESIaMEMmQESIZMkIkQ0aIZMgIkQwZIZIhI0Qy ZIRIhowQyZARIhkyQiRDRohkyCUpZJNF4kABVNMBTVPBth1Qta9AMWfDy+fvB80p+N4R+AIU6AHQ FGX13b5zoURuUNmEmJoFOXsWzNP3g0HKkR+x3SnWoj7D/VbWNPim+Bh0970FmmrQd46ugu5ARhZE EGKCSaZHHob7yPWmdQSJU3/xNlgb9rp6dGlFwuJIcheOrVbL3wGEBggx3Rf6yO03LUiQDQYYh/4N Zn47lSCUWB30lUl3yZh5YzfcPfcPWlYZWvD/3oLwEYK2AkY7ItVPGtjVaWG/RSdZ1dzVbAd+i/uW V5b80pWint2g2675G1MD5eCwBY7htCwxfglxVxw/yCSg6sbMuSu58i297+9gFn8Cht5GVzV9504g qhbVWaDOwMybQ9A9d9mtWCHHsG2hLfLaQcQRafdb1PloRRUWkBBtpCNxZU+trJWqQNulEhMWL/4a Ov87AaZr7EXORBSIlQPrSKWerrQWKT5CiD1DlLF7ElX0ViuqCM3QGjZotGlo5G+O/iCVk4H9cwYd +ncrkVK3hKD7qgwsVXR5g1UDSs7CK9+F9eaXvveeihOpOvO5ckvZE5/B0JR2hQxMJ6qIOl8tp9fT 7mIl7L9Tp04JLQKSQcYKsM6qkDGrbwD9eXcxDLtR7XNA/287osGDf9waWj/3YjuYk68Q/E5UG13F IuH7VV5eui0nCINub8RqDAM1ninVFQ6WfbZK4m+gGnXUTuoMdHf3wq2Fhchvjw59B576YcV2FNR5 +r8GleebsA3uG/og0M6+PbvJ+YvvBtu1HFByqu+5GU5CaGBol22ijYuzKmXFgG+6HoWNT7+buJNI tqEYvndJB/rgtl5ybfJ/sW2441Gw/xj9g1L18FBloQcZ0g6/QNh++Qhxvxvb+BpAmDpJ4gKnkRI0 0Ibq/2bSgfITV1papKmXXN6/cFKtZHeM7KTX+uO+//DGR7Bly5bU/VwtogmBeEnxjCnaHUXbGNth 1Mv5QrvvXZKBnjhxghw7dqz2jGQYbQVajyeq7DiJvSocH0vo1NQUbN68OfS7UhDi4ZORB4jI5USP yxiwYjus53LEsm3fuyQDFU1O4LeUup6tz9ozvq9SEUIzvx+Og37+2cgiSIre/5lQUsL0dT2EsBMn IuTq1atk586dgd/M6qC/98A2YO0SfpfaHhesas25Y1s0zcr2QwNjLjqexPdDMKtqO2BPtEdGzzQY 23Ma9N5nQjvNT97Zs2dh//79qQnBCTItgUSG2Aa2zSf7+oCX1KRotKQkJ6QK1Lvl//wBjH/9Tpx3 CjH2aV3eqHoIESlRntNaQDpCEF7OSX2py3UNrdAy6BaXeg9Bcc9oZQBhHk1CfX/06FFy8uTJ0N/4 CeJ1PzoAHZ3FuiWCxbrOTpibn5ePkBrcSS6by/Dta5uEgeT8wc+hvWND0EVNutoEKsgnKQI3ln2P dZYXS5H94SXsxsvb4J7Ba03JiSXaU4+Eu7oNrQDGr2YI+fo8mG8+TlMqPIpn7oV9Z3YF60cEa2Ht uO5sIIZB4MrH9Mvw8LCi53Xfb1QCq/Xx0fdJzf+tW19/XusTEsZKFPUwR1TMIhM4+DdQevY1jJjV SQgH9F6mR7fDRnUqQAzmn+JcXnZlXrlyBXbs2CG0QSzQHkVKYIiEvHf5MoR5YHw7VAJfXOm3l+UW OS+rwZoS4gGJWb44BPmp8RoxmATk4SOEm7Qogx+Ve0L9zue5RITQNtg4wyOEK4v5sYEf3QwdJ7r6 S1Y3dD4zvWbucEMI8UD350vXAF59KEAIG20j+KhZ5IGFBZg8WNvCxyMofewzIooQ7Kfy6Z9BvfBs pFeJG2K3tC5oH7656lR/QwnxEJpUTGDQaeqG0fUYB0UFhDz2/mwXvHPhUmR6JZBTqxJy7tw5cuDA gcB7HMPyhSNQvD4W2aaXcF1/8FLdDkBzCKkzqRhIXwiicB5x0TyvwjxpikuZJDmVQ7e2Dy2Clid0 jylunCyaQki9SUVRDmt+dpqsu+ve6DaZJGMcIYcPH4bx8fHESUW6s1q6QVWxCKjKnMHlVPalKYSE GeK6CGEkhF/JvF3wJIS3TcePH4cXfvMCRNmrNFlelBZyWg919X3l9ib3yJpCSNJUBh+5R+WwcMuV 9ajo+5LpW/Xbe7fC+9cnlbAJDtiJCG8srE8BuHXmRnugS/lKOLY5cncib+z2H1FkwQ0cPRwWKBE4 wbx7++3CfKAuZnF5MrzgD5OLSdpHIEHCBeXW6Rr8ApZ2/J6qqCggYZiYFe3t0/akkpAQ9RBXl1U3 opwXm4eKVEuCFE0SSZl9dSM9jBF3kE90EqbxhAgGySNUXwvqh+0O9vf3k4mJCV85PuZJs+El7BuH VOeiB8IJboqE1AtvgN5WMephRGn9I1DYsB06v38QlOImeh/FUXTADLRdUmpHWPHMmKnCymn6NKdG kubZ2P6mOLGDMYviemD8gpKaEAS6mKI0f6Jv4MbZUHMOzM1fGCTtk2OJDpJ/ogSPJklPCMI7LBfn XoYBD9at6/8odYBWF+o4rG4O+dVuSxCCoD7/aFuqw9fo/8PWfroX3tArCnjmwOVh9kzlrkqa6xwt SwhitfdXUFq6n3iN3i/Bq3qW2lOffakCJRft1PytGci/vomekkzbN97jailCKPCwxWl1TS4VeShX E5/0JGbfCBB9PZhmEZR8W6WAUnEQvMuuC5eOgfPBX2ODwSTt8lc5Wo8QqKiv3EsGOLpVI8a7q1J6 6mO6WvEiEN7Uotfi6rhj0gxgMFn48W9bz6iHggnEEIu9AysHKkLKdTizNacg7qZWMxB12rN1CUFU J7uzfyb5/kM1vpj5yy7S8+U/fe500itzqbtZlV6UWuWnI8JEY2sTAtXgsd477nZl8OghIaHoNOB1 uvzkn6iao0dkq1KFeSq8Q4lq0LskxIIlkS2Ldy+tn79MvT26aGICztWdOpEAdJBanZW9VH7tsV1x 1R7A7hE6vYY3cZi+0bAhk2jVqw2OZtHMAHpo9GKr9zeGIa4TYGCWwH2P5XUkwZPgmIXT8hJyp0Gu 9HuGjBDZkBEiGTJCJENGiGTICJEMGSGSISNEMmSESIaMEMmQESIZMkIkQ0aIZMgIkQwZIZLh/wAA AP//AwB6PNKZjxKvLAAAAABJRU5ErkJggg== --Apple-Mail=_23E0C4A9-5D33-4C85-8425-0C8C1C96FB96-- --Apple-Mail=_C1EF28E8-56B4-4ECA-B066-089EB9168571--

To be clear, this is what the message looked like when it arrived to LISTSERV. LISTSERV is generally not adding the HTML code, or encoding the attachment. As far as LISTSERV is concerned, it is just including a copy of the message as it received it, plus any top or bottom banners that the mailing list is configured to add.

Any method used to convert the notebook files to another format therefore need to take into account, not only the way that LISTSERV stores the files, but the email standards that govern how email messages are formatted within those files.