maildelay

Delay mails and deliver them according to a set of rules. More flexibility, less disturbance.

Why

We all get too much mail, don't we? If you are subscribed to some high-traffic mailing-lists (and/or you have many mail accounts) you know the problem that you get mail every few minutes and it distracts you from your actual work.

Current solution: Check mails N-times a day, otherwise ignore them. Hm, but there are mails (from your mom) that require immediate action! What we really want is much more flexibility! Wouldn't it be nice if we could specify rules like:

• If I am at work, make sure that I get mails from the high-traffic box at most every 2 hours. Send them accumulated, but between these bursts I want silence from that box.
• I want silence during my work hours, but otherwise deliver the high-traffic mails immediatly (because in my spare time I have nothing else to do anyway).
• Deliver mails from box "foo" at 9:00 and 15:00 o'clock, otherwise shut up.

Solution

• Old setup:

getmail/fetchmail -> procmail -> maildir/boxes -> imapd/client

• New setup:

getmail/fetchmail -> procmail -> maildir-fake/boxes
maildelay (cron-job) -> maildir/boxes -> imapd/client

Example Config

[DEFAULT]
default_buffer_mdir: ~/.maildir-fake
default_real_mdir: ~/.maildir

[Box:OpenBSD-tech]
buffer_mdir: %(default_buffer_mdir)s/OpenBSD
real_mdir: %(default_real_mdir)s/OpenBSD
rules: WorkCollect, Immediate

[Box:Gmail]
# yes it is clever enough to derive {buffer,real}_mdir
rules: Fixed

[Box:Yahoo]
rules: WorkBlocked, Immediate

[Rule:WorkCollect]
action: collect
from: 09:00
to: 17:00
days: Mon, Tue, Wed, Thu, Fri
for: 120

[Rule:Fixed]
action: fixed
at: 15:00, 20:00

[Rule:WorkBlocked]
action: block
from: 09:00
to: 17:00

Rules/Actions

Rules are always evaluated from left to right. If a rule matches, the other rules are not evaluated.

If a rule specifies a "days" string, it has to match the following condition: 'if datetime.datetime.now().strftime("%a") in days'. If "days" is not specified, the rule is further evaluated on every day of the week.

• immediate: Immediately deliver mails. This is an implicit rule that is always present. It is mainly used in cascaded rules as the last rule. A practical example could be a "Box" that specifies "rules:" as "WorkCollect, Immediate". Therefore in the working hours "WorkCollect" would match and the user does not get disturbed by high-traffic mailing-lists. In the spare time "WorkCollect" does not match and "Immediate" is executed, therefore mails are delivered instantly.

• block: If the current time is between "from" and "to", do not process a single mail from that box.

• collect: If one mail in the buffer box is older than "for" minutes, all buffered mails will be deliverd. This rule is perfect if you do not want to get disturbed for the specified amount of minutes. It is like a mail digest that is sent every "for" minutes. In between you do not get disturbed.

• fixed: Deliver mails at the specified points in time. If the current time is larger than the current "at" and the mail is oder than "at", it gets delivered.

Todo

• Make it at least look like python and not like a drunken monkey wrote a shell-script using python.
• More testing! It looks ok, what could possibly go wrong? For now it never ever moves mails, it is always in "dry-run" mode.
• Maybe allow a "custom" action (needs an API).

Synopsis

usage: maildelay.py [-h] [-c CONFFILE] [-f] [box [box ...]]

Delay mails and deliver them at specified points in time

positional arguments:
  box                   zero or more mailboxes matching names in
                        configuration. If none specified, all mailboxes are
                        processed.

optional arguments:
  -h, --help            show this help message and exit
  -c CONFFILE, --config CONFFILE
                        path to configuration (~/.maildelay.cfg is the
                        default)
  -f, --flush           flush the given (or all) mailboxes (i.e., apply
                        Rule:Immediate)
  -d, --dry             dry run. Print which files would be moved, but do not
                        move them. Currently, this is enabled by default and
                        can only be disabled in the source code. This will
                        change if the code is considered stable.