sendmail, 4th Edition

Keep Messages Small

Many businesses routinely reject messages that contain attachments, or accept them and silently strip attachments. Mailing list management should adopt a similar sort of strategy when accepting messages that will be broadcast to subscribers. To protect the recipients of the mailing list, either reject submissions that contain attachments or silently remove attachments (perhaps with an indication of that removal placed in the body of the message).

The method for rejecting or removing attachments varies depending on the type of mailing list software you use, and therefore, we must leave the discovery of that method up to you.

Some lists discuss matters that, by their very nature, require readers to view or hear examples. When administrating lists that discuss images or sounds, for example, try to encourage list members to send web references instead of embedding the images or sounds directly into each message. The following lines illustrate one appropriate technique:

I put my latest 3D images up for you to see at
http://www.my.domain/3d/bob/newimages. Let me know
if you like them.

Here, a half kilobyte message distributes images vastly more efficiently than would a potentially two or three megabyte message that embedded the images directly inside itself. Because of that efficiency, use of references is kinder to ISP machines, and reduces the risk that the images will be removed or email rejected because they have attachments.