Out of the box, phpBB does not provide the ability to send regular e-mails to users with postings on the phpBB site. phpBB expects that users will visit the phpBB site regularly if they want to keep up with what is going on at the site.

phpBB digests are just e-mails sent to users periodically with a summary of postings made on a phpBB forum. Weekly or daily digests are available. Digests make some phpBB users' lives easier. They don't have to explicitly visit the site to see what conversations are going on around there. They just read their digest and if there is some topic that seems of interest, they click on it in their e-mail program and start participating! They can unsubscribe at any time. By default, weekly digests are sent on Sundays. The user determines the hour they want to receive the digest. Whatever time they choose, they will always get the latest news so they can pick a time that suits their lifestyle.

What time period is covered by the digest? Either 24 hours or 7 days, depending on whether you selected a daily or weekly digest. Messages older than this will not be sent. In addition if you want, you can elect not to see messages since you last logged in, if you visited recently. You can even filter out your own messages.

If a user does not want summaries of every message, they can be selective. They can pick the forum or forums that interest them. By default they will get messages for all forums that they are allowed to access.

Digests can be sent as e-mails containing HTML or plain text. Unless the user's e-mail program can't handle HTML (very unusual these days), HTML is recommended. Frankly, text digests look pretty plain and are harder to use. That's the nature of plain text. By default the user gets the entire post as text, but they can also select to see excerpts of each message. They can select the first 50, 100, 150, 300 or 600 characters or the full text of the message. An excerpt reduces bandwidth and is usually all that is needed. Why? Because each message has a convenient link that will take you to the topic or message of interest.

This hack requires a "cron" or similar operating system utility that can wake up once an hour and call a program called mail_digests.php. This program sends a digest to anyone who subscribed to get a digest at that particular hour.