Bulk mailing attachments: size counts

September 04th, 2007
By Luca

When you send bulk mailings, most of the times adding attachments is not a brilliant idea (= bad idea). It takes a lot more time for the mailing to be completed, and many antispam spam check score filters on recipients’ server may be alerted. But the most important thing is that people receiving your mailing could become upset, expecially if they are on a slow connection. Instead of adding an attachment to your e-mail, it is far more sensible to upload the file on your website and add a link to the file somewhere in your message: if someone is willing to get that particular file, he will be able to download it at a later time. This operation will also lower your final email spam score rate (attachments are usually marked with 1 to 2 html email spam points, versus 0,5 spam points of the common textual link).

Here’s an example of html hyperlink that you can put in your mail:

<a href=”http://www.my-server.is/not-spam.zip”>Click here to download</a>

But there may be situations where attachments are really needed, expecially in small distribution mailing lists. In this case, it is very important that you send a single archive (which will contain all the files you are distributing), and that it is as small as possible. Not only because people receiving your e-mail will prefer small attachments, but mostly because you will save bandwidth and time when sending.

You may think that 50k more or less makes no difference; but when it comes to bulk mailings, it does. Let’s suppose you are sending 2000 messages: since each message is sent separately, this means that 50k less on the attachements will save you 50k x 2000 = 100 Megabytes. Even if you are on a fast connection, this is a considerable amount of time saved.

This is a very good reason to use a better compression tool than the usual .zip format, but stay away from unknow and obscure archive types (your recipients would not be able to open the attachments); .rar archives are a good option, as .rar format is very popular (most of people have WinRar installed on their system - and you could add a link to the unarchiver anyway) and has an excellent compression ratio.

Whether you are delivering a small email newsletter or a large bulk mailing, always remember that smaller is better.

(ps: this article comes from the bulk email software news archive)

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20+ hints on better spam check optimization

August 24th, 2007
By Luca

This is a follow-up to the popular “Hints on better sending” article from September.
If a large part of your messages are not delivered, chances are they are being deleted by antispam filters by mistake, and then marked with a Spam Message Tag.
Here is a list of guidelines you can follow when creating your messages… and never wonder why my email goes straight into spam folder?

1. If you’re using HTML emails, include a text part in the email as well, for recipients (and anti-spam checkers), and keep that text as close to the HTML copy as possible. The closer they’re related, the less likely your email will be seen as spam.
2. Keep your message’s layout as simple as possible. Avoid complex formatting (yes, it will make it look better, but less people will receive it).
3. Pay particular attention to your mailing’s subject: never use exclamation point (!), CAPITALIZATION, and words as “free”, “guaranteed”, and gappy text (t h i s i s g a p p y t e x t)
4. Avoid generic salutation formulas as “Dear User”; it is even better to avoid salutation at all.
5. If you’re using HTML emails, use high quality HTML emails. Don’t use tools which generate horrendous HTML (example: MS Word). They often leave signs behind (like empty tags, eg: ) which are generally found in spam. Unbalanced tags and invalid tags will also flag an email as spam. If you use a title, make sure the title is meaningful — the default titles generated by HTML tools are often used as spamsign.
6. Don’t insert active components (javascript, ActiveX, plug-ins) in your message. If you need rich media content, just link to a media-rich page on your web site.
7. Don’t insert too much graphic in your message, too much images will alert the spam check filters. Your message will get lower the lower spam check rates the less images you use.
8. Avoid attaching files; use links to files hosted on a web server instead.
9. Use email composition and mailing tools that work correctly. Well constructed emails (technically correct) can be readily identified as not-spam. Emails with missing mime sections, invalid or missing message-ids, invalid or missing date headers, subject or other headers with unescaped unicode, etc., are frequently signs of spam.
10. Avoid useless or needless encodings. Don’t use base-64 encoded text unless you need to.
11. Don’t include a disclaimer that your email isn’t spam. Don’t claim compliance with some legal criteria, especially one which is not actually law in your country. Only spam needs to claim compliance: non-spam is supposed to already be in compliance.
12. Use normal conversational language, be sure not to use excessive spacing and or capitalization on your subject.
13. Do not use “cute” spellings, Don’t S.P.A.C.E out your words, don’t put str@nge |etters 0r characters into your emails.
14. If you’re using HTML emails, do not use invisible web-bugs to track your emails. If you must track your emails and whether they’re read, use visible graphics as part of your email, not invisible graphics.
15. Don’t include gratuitous references to spam subjects. Don’t talk about rolex watches, sexually oriented activities or drugs, or debt treatment, unless those topics directly relate to your email. And if they do, limit your email to one topic at a time. An email which mentions rolex watches, Viagra, porn, and debt all in one email will very possibly hit several rules that flag it as spam, even if everything else is clear.
16. Don’t use tools used by spammers (i.e., advertised in spam).
17. Use a well performing, well administered and trusted SMTP server. Most undeliverable mails come from poor SMTP services, which often lead to being blacklisted: make sure your SMTP service’s staff is ready to help if you are blacklisted by mistake.
18. Make sure your privacy policy, including enforcement, and including query contact information, is easily found and clearly stated on your web site. It’s good to include this information (where to find this policy, contact information), in your emails. Again, people who need to find out whether you’re spammer will often look for that information: this will help you in staying out of blacklists.
19. Be careful where you advertise, and be careful which advertisements you carry. If you advertise with companies that send out spam, your domains will be flagged as being related to spam. If you carry advertisements for those who spam, your domains will be flagged as being related to spam.
20. Be careful which domains/companies you allow to advertise in your emails (if any). Allowing spammers to advertise will get your emails flagged by the URI blacklists. On the other hand, don’t advertise your domains with spammers — having your domain name listed in their spams can also get you flagged by some URI blacklists.
21. Install and try our little free Email Mailing Check Spam Rate Software, and know what spam filters think about your email.

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