Welcome to MailBounce!

If you run an Internet mailing list, then you probably need MailBounce.


MailBounce is the intelligent way to process bounces from Internet mailing lists. MailBounce is currently being used by list owners around the world, on lists ranging from 20 subscribers to more than ten million subscribers. It has successfully processed real-world bounce files in excess of 40 gigabytes, containing nearly two million unique bounce addresses.

MailBounce recognizes more than 99% of all bounces in typical bounce files.

If you're tired of wading through piles of e-mail bounces and sorting them by hand, or trying to write your own bounce-recognition software that can recognize and process hundreds of different bounce formats, then you have come to the right place. MailBounce will process, classify, and sort your bounces for you, and will create a pre-formatted file of defunct addresses that you simply send to your list server for removal. MailBounce recognizes nearly 300 different bounce formats, including many obscure formats that are difficult to recognize or understand.

It works like this:

  • MailBounce reads in your bounce file(s) and sorts all of the bounces into four categories:

    • "Hard" bounces -- "User Unknown", etc.
      MailBounce will track and remove them if they bounce too many times.

    • "Soft" bounces -- host unavailable, disk quota exceeded, etc.
      MailBounce will track and remove them if they bounce too many times.

    • "Redirects" -- a new address exists for the user
      MailBounce will replace the old address with the new one.

    • "Unsubscribes" -- unsubscribe requests found in your bounce file
      MailBounce will remove the user from the mailing list.

  • MailBounce separately tracks your hard and soft bounces, and compares them against "bounce timeout" thresholds that you select. (You may select different thresholds for hard and soft bounces). Bounces that exceed the threshold(s) are marked for deletion.

  • MailBounce then compares all the marked addresses against your subscriber list to verify that they are actually on the list. If an exact match is not found, MailBounce will "fuzzy match" the address against the list; this accounts for differences in addressing schemes, such as user@domain.com versus user@mail.domain.com.

  • Finally, MailBounce creates a file with "delete" commands for all of the defunct addresses on your mailing list. This file is created in a format that is understood by your list server -- you simply e-mail the file to your list server for automatic processing.

That's it!

Platforms and List servers supported by MailBounce ...

MailBounce currently runs on Macintosh, Unix, and Windows platforms, and is compatible with the following list servers: Autoshare, LetterRip, ListProc, LISTSERV, ListSTAR, Lyris, Majordomo, Macjordomo, MReply, NTList, Post.Office, and eMerge; MailBounce also works well with "manually-managed" lists.

Some important notes about the list servers that MailBounce supports:

  • It does not matter what platform your mailing list is hosted on, since MailBounce is designed to be run "off line" from the list server. For example, your list can be hosted on a Majordomo list server running on HP/UX, and you can process your bounces on a Macintosh (or Windows) machine without any problem.

  • If you use a mailing list server that is not listed here, we provide a simple form that you can fill out and e-mail to us so we can support it in the next release of MailBounce.

Documentation, downloads, etc. ...


Vincent Sabio
Smart Mail Solutions, Inc.

Columbia, Maryland, USA

Page last updated: 01 November 2006



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