2. Email

2.1. Playing Nice with Linux Email Recipients

Many Windows-based email programs (such as Outlook) and some Linux based email programs (such as Mozilla) are enthusiastic about sending HTML-formatted emails when not strictly necessary. This can be a security problem for the recipient, breaks mailing list digests, and is Simply A Bad Idea.

For information about configuring your email client to not send HTML email unless necessary, see:

http://www.expita.com/nomime.html.

Another habit of many Windows users is to send Microsoft Word documents when a plain-text email would work. If the document would look fine as plain text, you can simply open it in MS Word, select all the text (control-a), and paste it directly into the email. If you have fancy formatting, but you don't expect the recipient to modify the document, you can format it as a PDF file.

For information about converting Microsoft Office documents (including Powerpoint, Excel, etc) to PDF files, please see Section FOO.

2.2. Linux Mail Clients Attaching to Windows Mail Servers

If you're looking for a graphical mail reader, both Evolution and Mozilla can send and receive mail from a Windows mail server, using SMTP for sending and either POP or IMAP for receiving. Configuration is straightforward, and it's also easy to tell the client to use SSL encryption when connecting to the server. SSL encryption both keeps your mail password safe and keeps some people from snooping the content of your email.

Evolution has a commercial gizmo which allows it to connect to MS Exchange servers and do all the calendaring and other fancy things that MS Exchange allows.

If you are using a command-line mail reader such as mutt, you will want to use fetchmail to actually get your mail. The fetchmail manpage has enough information to set up a normal setup. We recommend using SSL to keep your password secure; that is explained in the fetchmail manpage.

2.3. Windows Clients

Both Outlook and Outlook Express support POP, and Outlook can also supoprt IMAP. The advantage of using IMAP is that it allows the mail to remain on the server, which is handy for backup purposes and also for other reasons. On the other hand, POP is simpler, less likely to have security holes.

The usual Linux IMAP server is not totally compatible with MS Exchange. MS Exchange allows a folder to have both subfolders and messages, and MS Exchange also allows folder names with forward slashes (/) in them. The Linux IMAP server does not allow either of these.

Another option is a commercial product from SCO, SCOoffice Mail Server, which is advertised as being able to provide all of Microsoft Exchange's features to MS Windows clients. Presumably it also allows Linux clients to connect.

Linux POP and IMAP servers do not support SSL security by default.

2.4. Setting up SSL for your linux server pop/imap/smtp service

The program stunnel can be used to add SSL to your Linux server's POP, IMAP, and SMTP services. In order to avoid passing plain-text passwords over the network, we recommend requiring SSL for POP and IMAP services. For SMTP, SSL and authentication can be used together to prevent relaying spam.

XXX more info here: example stunnel setup for POP and IMAP.

XXX For SMTP, how do we set up authentication? SSL is similar to POP, but it needs additional stuff.

2.5. Mail-specific Backup Issues

If you are not fully backing up your user's machines, then most organizations at least want to back up the user's email. With IMAP this can be done by leaving a copy of all your messages on the server as well as the client (XXX how to configure this in Linux and Windows.) With POP, however, the server doesn't keep copies of messages, so we recommend backing up the client's entire disk.