Even when you send a legitimate email message there are great chances it will be checked by your server, the recipient server or both of them. Nowadays it is a common practice for system administrators to use spam checking and anti-virus software directly on their email servers. The idea is to eliminate or reduce the relaying of spam messages and the spreading of viruses thru the emailing system. On one hand checking messages at server level can drastically reduce the amount of junk that will end up on your mailbox but on the other hand that system is far from being perfect and as a result, legitimate emails will also get caught and will never get delivered. Such messages are called 'False Positives'. On average, 15% of legitimate messages do not get through to the inbox because of the false positive problem, and the rate is increasing along with the volume of spam. You will find more information on False positives and messages that never get delivered here.
This document briefly delineates a number of measures to keep your spam score as low as possible, to enhance the chances of reaching the inbox of your subscribers and to avoid your message from being placed in the recipient junk box.
Make sure your message content is not 'suspect' and doesn't look like spam
- Avoid phrases and wording spammers commonly use.
- Avoid using all upper-case words in the message subject.
- Do not use (too) many images.
- Properly balance your pictures size with the text size.
- Avoid using HTML tags that could increase your spam score, e.g. iframe tags, multiple large font tags and/or color font tags (better use inline CSS styles instead).
- Correct any HTML coding errors in your messages, since these too will increase your spam score.
You can check your message using MaxBulk Mailer SpamChecker, run your email through some of the spam filters available online, or install some end-user antispam applications on your own computer, and send an email to yourself before attempting to email end users. There are some services you can use to test the spam score of your e-zines and e-mail offers before sending them out. SiteSell SpamCheck Report tests your message at no charge using SpamAssassin and sends you a report (send your test e-mails to firstname.lastname@example.org typing the word TEST capitalized in the subject, followed by the message subject, Ex: TEST My newsletter).
Avoid sending attachments other than pdf, gif, jpg and png
Be careful with sending attachments other than .pdf, .gif, .jpg and .png files. Attachments like .zip, .avi, .swf, .exe, etc., may trigger spam filters or anti-virus checkers.
Spam is not only about CONTENT, but also about CONSENT.
Spam is the abuse of electronic messaging systems to send unsolicited bulk messages indiscriminately, commercial and non-commercial alike. There are a number of reasons that you should not send spam messages:
Spam doesn't work, most email users will never respond to spam messages and will most of the time delete them right away. Spam will damage your reputation, most people associate spam with disreputable organizations they don't want to do business with. There may be legal sanctions for sending spam, a number of states and countries have enacted anti-spam legislation, and it is likely that more will follow.
The following guidelines will help you avoid being identified as a spammer:
Always use opt-in email lists, lists of addresses of people who have agreed to receive email from you. Always remind people that they have opted in to your list, use a simple footer line like "You receive this message because you are a subscriber of xxxxx". Always tell people how to remove themselves from your list, when someone does ask to be removed, do it promptly. Always use a valid reply path, so that recipients can contact you by selecting "reply" in their email software. If you receive a spam complaint, handle it promptly and professionally. If you do not already have a procedure for handling spam complaints, you should create one. Never sell, rent, or trade your email list, if you do, you will lose the trust of the people on it and the permission to send them email. Never purchase email lists, only use lists of addresses of people who have agreed to receive email from you. Create a web site, add a subscribe form and collect email addresses the right way!
Limit your sending speed
Sending many messages in a short time span is often considered suspicious behaviour from the point of view of (web)mail providers. Try to limit the number of messages sent per hour by using the MaxBulk Mailer throttle settings like 'Group' and 'Interval' as explained here.
Customize your messages
If your message looks like a regular private email and you use tags to make it different from the others, you will get much better results with spam checkers. The idea is to make both the recipient and the spam filtering software believe the message has been sent manually to that recipient only. There are several ways to make each message different, you might for example start your message with:
where [Firstname] is a MaxBulk Mailer tag that will be replaced by each recipient firstname (Ex: Hi Joe,) or in case you don't have that information for all your recipients you might use a conditional statement such as:
where we will use 'Dear Friend,' in the case the firstname is empty. More information on conditional statements here. You might also add the following at the end of your message:
This message was sent to [E-mail Address]
The tag [E-mail Address] will be replaced by each recipient in your list. More information on tags here.
In time, a portion of the users on your lists will eventually change their email addresses. This may occur quite frequently with popular 'disposable e-mail addresses' from webmail providers like gmail, hotmail, yahoo, etc. A number of those users will not bother to contact you to update their email addresses and as a result all the messages send to them will bounce. Since sending messages to many non-existent users is likely to look suspicious, you should make sure you regularly process bounces to clean up your user lists. You can process bounces with our eMail Bounce Handler.
Check that your setup complies with RFC standards
Since spammers usually do not comply with (all) RFC standards, anti-spamming measures adopted by e-mail providers will tend to include a number of checks regarding RFC compliance.
- Make sure you have a postmaster account (email@example.com) for your domain.
- Make sure you have an abuse account (firstname.lastname@example.org)
- Analyse the email header of your messages and check for errors.
Check your Domain Name Server (DNS) configuration
Some mail services do a reverse DNS lookup to verify that the IP address that the mail is coming from is registered to the domain that claims to be sending it. If you domain is not properly registered, you messages may be treated as spam and thrown away. Indeed a badly configured DNS may trigger spam protection tools used by the mail providers of your subscribers, and your messages risk being rejected or marked as spam. You should therefore check your DNS configuration and ask your host to correct any DNS configuration errors (and warnings) you may find. Services to check your DNS are available on the Internet, for instance:
- Setup SPF or DomainKeys. - Use Bonded Sender or Habeas so you message will be recognized as legitimate. - Consider requesting inclusion in the 'whitelists' of important mail providers.
- Ask subscribers to 'whitelist' your From: email address in their email client or spam filter application
- Do not disable double opt-in in MLM. Double opt-in (or "confirmed opt-in") is generally considered good practice and it will ensure that the users that subscribe really want to subscribe.
- Make sure the unsubscribe link is easily available on every message you send. If your subscribers want to unsubscribe and cannot find the unsubscribe link, they will be tempted to mark your messages as spam instead, in order to get rid of them. Eventually this may result in your domain being blacklisted. See also: Spam and Open Relay Blocking System