I have a terrible memory, so I write down even trivial requests (or if possible email them to myself) with the result that I'm probably pretty reliable.

(or if possible email them to myself)

This worked very well for me when I uses POP3 at home; if I thought of something at work that I needed to do, I'd email myself a reminder and then I'd see it in the evening, or next morning at the latest.

But now that I predominantly use webmail, I usually see it right away (still at work) and mark it read so as not to distract me from proper unread messages, and then when I'm home I may or may not see it on the list of messages still in my inbox "for referring to again later".

Possibly the single most useful feature in my personal MUA is the ability to add a "Queue: yyyy-mm-dd hh:mm" pseudo-header to an outgoing message, which is removed by the MUA and causes it to submit the message to an at job instead of directly to /usr/lib/sendmail. I get a huge number of these minor organisational things done by means of sending myself a time-delayed email so that I don't receive it until I am at home, or at work, or wherever. I don't think I'd now be able to migrate to any mail environment that didn't provide the same feature!

Ooh - clever!

(I also used to use it for sending messages to other people, delayed until after the next nightly build of my various free software. So I'd check in a fix for the bug they'd just reported, typically, and immediately send them a message saying "Try it now", which they wouldn't get until the version available for download from my web site had updated. Unfortunately, this occasionally made me look silly if the nightly build failed to happen. I always vaguely intended to enhance the queue feature so that the sending of the message could additionally be made conditional on some arbitrary Unix command returning a success status, but I never quite had the energy to think the details fully through and do it.)