1.  Avoid common Spam words and phrases

Most Spam checking these days is Bayesian, which means that that your message is checked using a fuzzy algorithm that tries to guess if resembles known Spam or Ham (good) messages (mainly by checking the frequency of common spam words and phrases).

You can use the SpamCheck service to determine the Spam rating of your message. Send your newsletter to spamcheck@sitesell.net with TEST as the first word in the subject line. In a few seconds you will receive a SpamCheck Report with suggestions regarding the newsletter content.

More details at spamcheck.sitesell.com

 
2. Send individual messages to each recipient

It is better to send an individual message to each recipient, rather than using multiple addresses in the BCC field because many spam filters (and many ISP's) automatically flag multiple recipients as spam.

To do this select File > Options in MailList King and choose the Sending tab.  Choose the individual messages setting.

Note that if you are sending individual emails you should also personalize the email as much as possible by using MLK's personalization features.

 
3. If possible send via your ISP's mail server rather than using a local SMTP Server

Messages sent from a mail server running on your computer may be flagged as spam because some mail servers will try to contact the source IP of the sending server (which will fail with a local IP address).

In MailList King select File > Options and choose the Sending tab.  Click the Settings button and specify delivery via Outlook, MAPI or SMTP.  Avoid using the "Internal SMTP Server" option.

If you do use the Internal SMTP Server:

• Helo Machine Name: Specify a valid, fully qualified host name, such as mail.mydomain.com or smtp.mydomain.com under File > Options, Sending, Settings
• Sender Policy Framework: Ensure you have authorized the address you are sending from using the Sender Policy Framework (SPF).  Most ISPs these days use SPF to block spam messages that fake an email address and usually originate from a non-authentic IP address.  You will need to authorize the address by updating the DNS record for your domain name. 
• Reverse DNS Record: Some mail servers (such as AOL) check that your mail server, as stated in the MX record of your domain, has a "reverse DNS" record, and that it points to your server. The reverse DNS is basically the inverse operation of a DNS lookup: given an IP address, it gives you the internet name.  To enable this (assuming you have a fixed IP address) you need to ask your ISP to have the reverse DNS record for your IP address point to the name of your server, e.g. server1.mydomain.com

 
4. Stagger the delivery of your messages

It would appear that some of the big mail hosts such as Hotmail will recognize when an identical message is sent to a large number of subscribers at one time so you should stagger the delivery of your messages (using the setting in File > Options, ISP Limits) and/or use the schedule sending function (click the down button beside "Send Message" on the message sending toolbar and select Batch/Scheduled Sending) to send your messages in small batches

 
5. Minimize your use of attachments

Attachments can cause your messages to be blocked, particularly the following:

• SCR, EXE, DOC, XLS, VBS: They are often used to transmit viruses
• JPEG and GIF: Some companies will block incoming graphics
• Large file attachments: Some companies will block large attachments to minimize bandwidth wastage and some mail servers do not support messages larger than 3MB

 
Other things to try:

• Review the Frequently Asked Questions for Spam Assassin, a commonly used Anti-Spam tool, in particular "Avoiding False Positives for Senders"
• Check that your IP address is not listed on a known blacklist of spam senders (e.g. using the tool at: www.robtex.com/rbls.html or www.aboutmyip.com)
• Try changing the "Identify Software As..." (XMailer) setting under Advanced Sending Options
• Watch the size of your message.  We've had reports that AOL, Yahoo and others will flag a message if the total size of the HTML (excluding attachments and embedded images) exceeds 50KB.