Email Not Reaching Some Customers

[dr00t]

I have been experiencing the weirdest problems with my WHMCS email notifications...

 

1. About 50% of my customers never receive their email notifications, whether it be a signup notification, invoice, invoice renewal, password reset, or an admin initiated email using WHMCS.

 

2. There is little or no consistency or pattern to the type of client not receiving the emails. Some clients are Google Apps customers, others work for offices hosting their own email. Although, all the tests I have run on my own Google Apps hosted emails appear to work fine. It appears to be more isolated to a WHMCS customer than a trend in email hosting service.

 

3. The emails don't go into a SPAM or Junk-mail folder like I would expect... they just don't get to their destination at all. Almost like a blacklist or firewall filtered them before they could even reach the inbox level. The domain and server are only a few months old and were never used to send spam or any type of "mass email" at all before. So the domain and server shouldn't be on any blacklist or filters.

 

4. The WHMCS admin panel acknowledges and confirms the email is sent, and I have switched between PHP Mail to SMTP and I get the exact same results for both settings.

 

5. Even the staff at WHMCS cannot help much because the tests they performed all worked for them... I guess they fall within the other 50%.

 

6. I am exploring the use of an external SMTP service, but was going to see if anyone else has experienced this type of problem with their WHMCS before I took those measures. Hopefully it's a setting somewhere that just needs an adjustment or maybe a bug? Otherwise, will an external SMTP service even resolve my issue?

 

Any help, thoughts, advice or support is appreciated. Thanks.

Edited August 24, 2010 by dr00t

[panamaserver]

remember when you sent an email there is lot of things that are out of your hands, and you cant go one by one fixing it because you are not the responsible of the destination email server.

 

each email server administrator use different rules to acept/reject an email

like

- PTR(RDNS), make sure the ip of your email server have a valid rdns.

- RBL (BLACKLIST), make sure your server ip is not blacklisted

- SPF, make sure your domain use a valid spf record

 

and lot of others...

[dr00t]

I figured it out... I guess the resolvers on my server were off and caused all the accounts I imported via WHM to use "Local" email settings when they were supposed to go via Remote services, such as Google Apps, etc.

 

Once I adjusted everything, all email now sends consistently and to all customers.

 

Hopefully if this happens to anyone else, they can consider it may be a server resolver setting issue instead.