This section contains some topics relating to email delivery.


The ~/Maildir directory resides on its own volume, and has a separate quota from the rest of your home directory.

Before copying over any existing email, be sure that you have enough disk space in your quota. Log into and run

fs listquota ~/Maildir

This will give you the name of your mail volume, available space (in MB), used space (in MB), the percentage of your volume used, and the percent of space used on AFS by all HCoop volumes.

If you need more space, just request a quota change using the portal.

Sub Addresses

All mail address support sub-addressing in the form mailbox+$address@domain which is delivered to mailbox@domain. This allows you to easily generate one-time use addresses that can be blocked by a filter later if the source ends up spamming you without resorting to a catch-all, and more generally to make it easier to filter your mail (e.g. ClintonEbadi uses clinton+amazon, clinton+paypal, etc. and procmail rules for filing them into folders).


Both Exim filters and Procmail are available. You can use either procmail or an Exim filter, but not both. Here are some considerations for deciding which one to use.

It is recommended that you not use procmail going forward because it has been unmaintained for about a decade, and can have reliability issues during delivery.

Please read the following subpages for specific information on each method.


If you want email sent to your HCoop email address to be forwarded elsewhere, you can do that as follows.

If you are forwarding to GMail: you must read Google's Best Mail Practices document to avoid causing all coop mail to be flagged as spam. Currently, what you can do on the delivery side is:

Official Mail and Gmail

Gmail has decided that official communications from Hcoop are spam for reasons they prefer to keep mysterious. To help you receive official communications, there are a few steps you should take.

Dealing with spam

Note that scanning for spam must be manually enabled for each account with "setsa on" from the terminal. A virtual account would use "setsa on".

Spam is an inevitable fact of life. See the SpamAssassin subpage for details on using SpamAssassin, which is our preferred solution to the spam problem.

Configuring Mail On Your Domain

If you use the domtool dom type and are using HCoop's DNS servers, mail will be handled automatically.

If you are using another DNS provider, you will need to:

Changing Default Behavior

If you are using Easy_domain, mail routing for your domain is controlled by the environment variables DefaultAlias and DefaultAliasSource. By default, $your-hcoop-username@$domain is routed to your local HCoop mail account. You can override DefaultAliasSource to use another address, or a catch-all. Additional aliases can be added using the emailAlias from to action. For example, assuming a hypothetical user alice:

dom "" where
  DefaultAliasSource = userSource "bar";

dom "" where
  DefaultAliasSource = defaultSource;

dom "" with
  emailAlias "bob" "";
  emailAlias "admin" "alice";

dom "" where
  DefaultAlias = false;
  emailAlias "bazquux" "alice";

See DomTool/Examples#Mail documents how to configure more complicated setups including aliasing a single address to multiple targets.

Virtual mailboxes

Virtual mailboxes are a good way to give someone a "vanity address" on one of your domains, where they can receive and check email. See the Virtual Mail subpage for full details on how to use them.

Mailing lists

Instructions for setting up mailing lists on your domain are available on the Mailing Lists subpage.