Avoiding spam filters for email validation

The legit automatic emails my service sends get filtered out

[bb22]

I have a perfectly legal and "clean" service I offer on the web, and never got involved in any kind of spam marketing.
When a user registers for the service, he is sent a validation email he needs to click to validate his account, as many other services you may know.
Now lately, I keep getting questions from newly registered users that they didn't receive the confirmation email, and the amount of unconfirmed accounts is increasing drastically. When I direct them to their spam folder they finally find the email, but many don't even bother to ask. This is making me lose users, activity, and ultimately money.
How can I avoid this phenomenon? As I said those emails are perfectly legit, and I can't figure what I can do to pass through spam filters untouched. It's really annoying considering how I keep receiving in my various email accounts protected by what's supposedly the best filters available emails containing such blatant spam keywords as poker, viagra, enlarge etc.

[FalseDawn]

Use dnsreport.com and check the MX and Mail settings displayed.

The biggest problem is not having reverse DNS configured correctly.

If your clients use yahoo, hotmail etc. free email accounts, you are unfortunately at the mercy of their spam filtering policies.

Also, make sure your IP is not blacklisted. You _do_ have your own IP address, don't you?

[edited by: FalseDawn at 7:44 pm (utc) on Sep. 6, 2006]

[bb22]

sure, I have my IP, reverse are fine, and address isn't from a free account...

[FalseDawn]

All I suggest then is to change the wording of the subject (and message maybe)
Avoid using unneccessary punctuation like exclamation points etc. and "theatrical" wording, if you have any.

[jtara]

Make sure you have an SPF record in your DNS.

As previously mentioned, avoid unnecessary punctuation, check your spelling, don't do anything cute with capitalization or spacing (V I a G r A!) etc.

Never, ever, use the word "free".

[stajer]

You need to be really careful with the text of these types of emails. Text that is natural for these emails is also common spam text. For example:

- confirmation email
- please confirm your registration
- email validation

etc. are all "hot" phrases that will get you spam routed.

[bb22]

Thanks for your help!
So basically, reviewing the welcome message to get fancy stuff out, and maybe including the user name in the email subject would help.
Should I change the email address used as the sender to make sur ibypass some sorts of blacklists I would have been put in? Is it important that the email address actually exists?

[Lexur]

I once received an email from a postmaster (Yes! There it was one!) where he explained me that they blocked any email address they detected sending more than 25 emails at once.

I suspect free email services apply same kind of filter.

[kaled]

Create accounts with hotmail, etc. and send mails to yourself (at those accounts). It should not take too long to work out how to pass though the spam filters.

My general advice would be to keep it as short and simple as possible. Most spam is verbose.

Kaled.

[onlineleben]

Sorry, not 100% on topic but highly related:
Anyone know how to get direct feedback from the ISPs re spam complaints etc? I read an article on clickz yesterday about this but it was't really specific.