How do I turn off my catch all email account?

[PWSowner]

With most new accounts, you have a default email account that is called a catchall account. Any email sent to anything@yourdomain.com will go to it if there is not a seperate account for it. Some people like it this way, but many people don't. Over time, you will find yourself getting a lot of spam to all kinds of email addresses.

If you would rather have only specified email accounts and not have everything go to a default email, you need to create a POP account or a forwarder for whatever you want your email address to be, then set your default email to blackhole.

To turn off the default email, go to your cpanel link for "Default Address" which may be on your cpanel front page, or may be in a mail page. On that page you will see "Change Default Address" and "Send all unrouted mail for [domain.com] to _____________. In the box, just put :blackhole: with the : before and after it.

This will make anything going to non-existant email addresses just disappear.

Just don't forget to either create a POP account or a forwarder if you want to use an email address at your domain.

[Roy@ENHOST]

Thanks for that one Mike, never knew about that.

How dya figure it out?

[PWSowner]

Experience

and reading it somewhere one time.

[rs-freddo]

IMHO you should really use :fail: not :blackhole: - if someone misspells your email address then they will believe you received their email and didn't answer it.

Better yet, place Active Spam Killer on your catchall and continue to use it. I find catchall extremely useful as I use a number of different email addresses (support@, info@, accounts@, sales@, michael@) and only need to download from one box. My clients often misspell my email address too (some can't even get the domain right).

You can also turn the catchall off right at the SMTP, so your server won't even except email not addressed to a non-catchall account. Of course that leaves you open to dictionary attacks (to find the email name), which uses CPU. Not in my opinion a good solution. I believe there is a tutorial by Aussie at EV1, if you wish to go this path.

[cpaneljosh]

On my personal domain I do the same thing squirrel does (change the default to :blackhole Unless someone is mailing my account directly they're spam. You can take it even a step further though. Those stupid spoof emails which invariably come back as rejects will go to your username mailbox even if you have a default set so I add a forwarder for the username account and forward that to :blackhole: as well.

I personally prefer :blackhole: over fail because it just deletes the email instead of trying to send it back to what's usually a bad email address.

[Juanra]

OTOH if the mail server is configured to verify the recipient :fail: is better than :blackhole: because the message is rejected in SMTP time, even before the message body is sent, which also helps save bandwidth and server load.

[dgbaker]

Juanra, can you elaborate on this? What changes to exim need to be done for this?

[Juanra]

Instead of simply:

accept domains = +local_domains

use:

accept domains = +local_domains
endpass
message = Invalid recipient account
verify = recipient

You can add this safely from WHM's exim.conf editor.

[dgbaker]

Thanks as always Juanra!

[rs-freddo]

Originally posted by Juanra
OTOH if the mail server is configured to verify the recipient :fail: is better than :blackhole: because the message is rejected in SMTP time, even before the message body is sent, which also helps save bandwidth and server load.

This will lead to spammers doing dictionary attacks in order to find the active email address. If you're going to do this, you should also implement Aussie's anti-dictionary attack tutorial at EV1 forum.

PS. Interestingly enough hotmail rejects incorrectly addressed mail at SMTP time and Yahoo accepts all mail and then rejects later. I have heard that hotmail has dictionary attack problems whereas yahoo doesn't...

[Juanra]

I've seen it but it relies on $rcpt_fail_count which is trivial for spammers to workaround.

[rs-freddo]

Jaunra does your code allow some people to use catch-alls and it works fine. But some people to disable catch-all with :fail: and have mail rejected at SMTP?

Or does your code turn the catch-all into a simple pop box?

[Juanra]

Not sure if I understand what you mean. Each user can set an existing account as their catch-all account (either local or remote), or they can set it to :fail: to reject all mail addressed to non existing accounts.

Same thing goes for forwarders. If you forward an account to :fail:, then it will be rejected by the mail server in SMTP time.

[rs-freddo]

Thanks for the reply - what i wanted to know was whether some accounts could :fail: their catchall (and have mail stopped at SMTP) and other accounts continue to use their catch-alls as normal?

But I think you answered yes, that your code only affects :fail: accounts...

[rs-freddo]

OK, I added the code and it appears that only accounts using :fail: get bounced at SMTP. Normal catch-alls still work fine.

Thanks for a very useful piece of code.

Just out of interest, I wrote a piece of PHP code to query SMTP for valid email addresses.
Basically it makes these calls:
HELO $this_server
MAIL FROM: <{$Email}>\r\n
RCPT TO: <{$Email}>\r\n

With Hotmail the RCPT TO call does NOT give back code 250
(250 means valid recipient)
Interestingly with your code and a :fail: on the email box
SMTP STILL GIVEs BACK code 250 - even though an email sent will be bounced at SMTP.

Just curious as to why this is so... if anyone can enlighten me...