Hi,

I've tried searching the list archives, and posting to the mailman-users list, but I can't seem to find an answer to my problem. Hopefully someone on this list can shed some light...

A quick background: At the non-profit museum where I work, we use Mailman to inform our paying members (and other general members of the public who signup to our lists) about our current exhibitions and events. We like to use HTML formatted messages with in-body (inline?) images for this purpose. It looks nice, and conforms with the overall look of our website and other publications in print. I realize sending out bulk HTML mailings is probably not the most typical use of Mailman, but it works great for us, and allows people who don't want our emails to quickly remove themselves without requiring our intervention.

Here's the problem: Today I sent out 2 test messages to a pre-configured list. For the two tests, the list had only 6 staff members subscribed.
The message looked great, everyone saw the content with the image correctly aligned in the body of the message, between the two blocks of text where it belonged.

However, after I added the 6700+ actual email addresses to the SAME list, and sent out the SAME email, the image was removed from the body of the message and included as an attachment instead. This essentially made our pretty little email look like crap. This behavior occurred on all the computers of the 6 staff members where I had previously tested, plus on additional accounts that I was able to confirm through phone calls, etc.

Again, the same list (same configuration), and the same email were used for the successful test and the unsuccessful real mail-out. I cannot stress enough that these were the *exact* same emails, for both the test with 6 users, and the later mailing with 6700+; the filesizes were the exact same, and the HTML was unchanged.

So... my only theory is: at some cut-off point, Mailman decides that there are two many users on a list to embed an image in every email. Perhaps because you thought it more efficient to store the image once and then reference it as an attachment when each member is emailed?

Or could this be some behavior of my mailer daemon, Sendmail?

Any thoughts?

Thanks in advance, Ryan