DAMTP Email Policy

Valid only for users whose incoming email is stored on the damtp email system (ie damtp accounts set up before October 2005, which are using the damtp email facility for storing their mail). Hermes has its own privacy policy.

Incoming email Most incoming email to damtp is shadowed. This means that a copy of the email is placed in the appropiate user directory. This directory is not accessible by anyone and is used to retrieve a message for a user if that message gets accidently deleted or lost. Email which is forwarded off site via the system alias file is not shadowed. In general shadowed messages are kept for between 5 and 38 days depending on their size, with small messages being kept longest. Should the shadow disk partition unexpectedly fill, we will need to delete older/larger messages to make space for the incoming ones.
Inbox Size Incoming email that is not automatically stored into folders or sent off site is stored in your inbox file. You are encouraged to save your email into mail folders and delete it from your inbox file. If your inbox file grows larger than 10Mb, you will be emailed a warning message and your inbox will not be backed up onto tape. Some incremental backups onto disk of your mail box may happen, but this will not fully cover you if you accidently say a year's worth of email from your inbox. Another reason for keeping your inbox within 10Mb, is to prevent the disk partition where the inboxes are kept from filling. Should this disk partition fill, email will not get delivered. When it fills (or comes close to) we take immediate action: we look for the largest inbox that is over the 10Mb limit and whose owner has being receiving warning messages about the size of their inbox, we move that offending inbox out of the mail spool into the user's mail folder in their homedirectory. This frees up space for everyone while continuing to allow the offending user access to their email.
Backups Email on the spool is backed up onto tape nightly, provided your inbox is a reasonable size. It stays there for approximately 100 days before being overwritten. If you accidently delete your inbox (or part of) or another mail folder, we use the backup tape to recover your inbox and then the shadow directory to recover the email you will have received since the last backup.
Leaving Damtp If you are leaving damtp please tell a computer officer (email help) your new email address and it will be put in the system alias file. This prevents your email from being shadowed, and saves us disk space. Your email will then be forwarded directly to your new email address. Should you need to change the address your email is forwarded to, please contact the departmental computing helpdesk from that address if possible, we will probably reply to your email before changing the alias, to ensure that you really really are who you are claiming to be. This is because we want to avoid the situation where we accidently forward your email to someone else.
Log Files The email log files are kept for 201 days on disk before being deleted. They are also backed up onto tape, where they get overwritten approxiamately every 100 days.
Spam We do not reject spam messages, instead you are encouraged to filter your spam messages based on the X-Cam-Score header. Here is a sample filter file which you can copy into your homedirectory to a file called .filter. See the Exim filter documentation for more information about exim filtering.
The Computing Service have guidelines about the use of bulk email which are equally valid in damtp.

Finally remember that email is not private, it travels in plain text across networks. If the material you are sending is of a highly confidential nature you may be better posting it, eg on paper or copied onto a cd-rom.

Please email any suggestions, corrections or errors to the departmental computing helpdesk

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