On 19/03/2021 07.31, Joseph Tam wrote: >> I've found the strip_attachments.pl script here < https://fossies.org/linux/Mail-Box/examples/strip-attachments.pl> which works fine on mbox (as tested on my local Thunderbird mboxes), but not on maildir which is on the dovecot server. My Perl isn't strong enough to re-purpose it. > > It you have anything that works on mbox, it will probably work on Maildir > as each file can be considered a single message mbox. You can combine > the script with > > find ~user/MailDir -type f ... -exec /path/to/mbox-strip {} \;
I thought that too, but my initial test on a single message file didn't work like that. I think I got a zero length file. I'll dig into the code to see if I can figure it out, although my Perl hasn't been used for 20 years or so ... > The ... can be replaced with more file tests (like minimum size or age or only within */cur/) to cut down on processing. Sure. I'm quite handy with find, sed, awk and all that bash malarkey. I was actually wondering if it could be done with those alone, but it would make more sense to use a library which understands mime already, and does the heavy lifting. This approach might be good as a last resort. > MIMEDefang may help. Nice. Thanks for the pointer. P. On Fri, Mar 19, 2021 at 7:31 AM Joseph Tam <jtam.h...@gmail.com> wrote: > On Thu, 18 Mar 2021, Plutocrat wrote: > > > I've been looking around for a solution to this problem. I want to prune > down > > the attachments on a server before a migration. Some of the emails are 7 > > years old and have 40Mb attachments, so this seems like a good > opportunity to > > rationalize things. So perhaps I'd like to "Remove all attachments from > > emails older than 2 years, in the .Sent directory", or "Attachments over > 10Mb > > anywhere in the mail tree" > > > > I've found the strip_attachments.pl script here > > <https://fossies.org/linux/Mail-Box/examples/strip-attachments.pl> > which > > works fine on mbox (as tested on my local Thunderbird mboxes), but not > on > > maildir which is on the dovecot server. My Perl isn't strong enough to > > re-purpose it. > > It you have anything that works on mbox, it will probably work on Maildir > as each file can be considered a single message mbox. You can combine > the script with > > find ~user/MailDir -type f ... -exec /path/to/mbox-strip {} \; > > The ... can be replaced with more file tests (like minimum size or age > or only within */cur/) to cut down on processing. > > I wrote a gawk script to slim down a multi-Gb Outlook mbox > for a user, but it wasn't really complicated, just matching for > /^Content-Transfer-Encoding:.*base64/i header (virtually all bulky data > will be encoded this way), buffering the base64 data part, then outputting > it if it was small, or deleting/replacing/extracting it otherwise. > > It was a one-off discarded tool but I can hunt for it if you're hard up. > > > I've looked at ripmime and mpack/munpack, and although they seem like > useful > > tools to do the job of deconstructing the mail into its constituent > parts, it > > doesn't seem to help in re-building the email. I think they could be > used > > with a bit of study into mail MIME structure, and used with a helper > script. > > > > So before I take a deep dive into scripting my own solution, I just > wanted to > > check if anyone else on the list has been through this and has some > resources > > or pointers they can share, or maybe even someone to tell me "Duh, you > can do > > it with doveadm of course". > > MIMEDefang may help. > > Joseph Tam <jtam.h...@gmail.com> >
