Gmail allows 150MB. Ok? And with that they are right. That is not “insane”. Insane is the opposite: to reject an email, because a single file attachment ended up a little bigger than expected. Total user experience disaster.
So could we concentrate on answering my question or solving the problem at hand? My system needs to accept mails up to 150MB (as of today, in the future it will likely be more). SMTP can do that. TCP can as well. The Internet certainly can. If it is outside of your imagination, I’m sorry. Handling a couple of GB with today’s computers and networks is a piece of cake. And I want it to be a piece of cake for my mail server as well. And there is zero technical need to inhibit proper handling of possibly large email. Most emails which pass are comparatively tiny for sure. But obviously I need to think with the limit in mind and not the average. And I need software which was designed with that limit as well. Is Postfix such a software? If yes, then it is my turn to configure it with that limit as well. If a user sends his photo archive via email in 150MB pieces because that it what my mail server announces it is not the fault of the user if my system goes down. Correct mail filtering should be possible without keeping the mail in memory and without writing it to disc twice. With that I mean: without writing the same thing twice. It should be enough to have it written before the filter and written again after the filter (possibly). Postfix can’t do that? Or can it? How? Regards, Robert > Gesendet: Samstag, 15. Januar 2022 um 20:16 Uhr > Von: "Bob Proulx" <b...@proulx.com> > An: postfix-users@postfix.org > Betreff: Re: How to filter email (DKIM) without keeping the message in memory > and without writing it to disc twice? > > Robert Siemer wrote: > > I need to DKIM sign possibly huge emails (up to 150MB). > > I know you say you need this. But even if you had it would it > actually be useful to you? > > DKIM is needed to interchange email with random email servers around > the Internet. Because said random servers will reject the mesage > without it. But no random email server around the Internet will > accept an SMTP message as large as 150MB. Therefore even if you had a > message that was DKIM signed you would not be able to use it to > transfer such a large message. > > You might have an associated site where you can coordinate and between > your site and another specific site the file limits might be increased > to allow such a large message. But in that case DKIM signing would > not be needed. Since in coordinating the configuration between two > sites for such a large transfer over SMTP it could be set up to allow > the transfer without DKIM between those two coordinating sites. > > SMTP is not designed to transfer large files such as this. It's not. > Much better to use a protocol designed for transfering large files. > Perhaps use email for notifications of and about the transfer only. > > Bob >
