While unsupported, iCloud still allows access to your e-mail via IMAP, and sending via SMTP. Apple has published the necessary parameters for manually configuring your e-mail client to use the iCloud service.

Server name: imap.mail.me.comSSL required: yesPort: 993 (is set by default)Username: example@me.com (use your @me.com address from your iCloud account)Password: Your iCloud passwordServer name: smtp.mail.me.comSSL required: yesPort: 587SMTP authentication required: YesUsername: example@me.com (use your @me.com address from your iCloud account)Password: Your iCloud passwordSSL is required  ...

If you wish to restrict SMTP access via IP addresses or a network range, one way to do it would be via Postfix configuration. You can set up restrictions using a Postfix hash-table or via a cidr file. You can choose one or both methods to perform the restrictions. The end-result will be the same.

Create a text file with the addresses you would like to reject. You can choose whatever file name you wish. E.g.: /etc/postfix/smtp_client_access

Its content should be something like:

192.168.0.1 REJECT Stop mailing us192.168.0.2 REJECT Stop mailing us192.168.1 REJECT Stop mailing us

Next, postmap  ...

A good explanation about setting up SPF-records for domains can be found here:

http://www.openspf.org/SPF_Record_Syntax

When you yourself are sending out e-mail to others, your recipients might complain about them not being able to open this e-mail. This is because you're probably using Outlook (with Exchange) and are sending e-mail in RTF-format.
Using RTF in a mail is generally a bad idea, because it's not an internet standard for e-mail layouting. RTF was introduced a while back by Microsoft, but has since been superseded for the widely adopted HTML; even Outlook 2007 now defaults to HTML.

So, to get rid of the winmail.dat, simply set your mail format to HTML (instead of RTF).

In Outlook, on the Tools menu  ...

Like any other MTA, Postfix has a maximum message size that it allows to pass through. By default, when not defined, it is set to 10 MB.
To change it, add/change the following in main.cf:

message_size_limit = 15728640

This sets the limit to 15 MB. To make it unlimited, set it to 0.

Versions 3.2 of SpamAssassin have (until very recently) a bug in their rules which would mark mails dated 2010 (this year) as being spam.

The reason for this is that a rule exists which would add an additional score of 3.2 to mails with a date set to 2010, because when the rule was created, the date would be in the very far future. Of course, this is no longer the case.

The bug was already discovered in 2008, and resolved in the SpamAssassin repositories, but was not backported to 3.2 until 2010-01-01, when the issue was discovered by Mike Cardwell, a developer in the UK.

Users with this pr  ...

In absence of a decent article, here's a good resource page for performance tuning of DSPAM:

http://dspamwiki.expass.de/Performance_Tuning

Spam nowadays is a real pain. While linux users are fairly safe against most common viiri and spyware, spam mail affects everyone.
While there are many spamfilters out there, I've found that only one is pretty effective, on the long run as well. This guide provides a solution to implementing this filter into KMail for local scanning, filtering and retraining.

A working KMail configuration for scanning and retraining spamfilter with POP3 accounts (IMAP is not supported because mail doesn't really get "downloaded").A DSPAM 3.6.x using the hash_drv, with training data stored in the user's homedi  ...

Got this link from a colleague:
http://www.linuxjournal.com/article/9454

It describes the inner workings of Postfix, the well-known mailserver for Linux.