Thanks to both people who replied, the response below gave me a clue, and lead em to a solution.
The problem was PTR records and reverse IP lookup. It seems more and more mailservers are doing a reverse IP lookup and comparing that to the banner. If they don't match your email will not be delivered. It apparently is a not entirely valid way to go about things, but it is none the less what is happening. Having corrected this, our emails are now getting through. PTR records have to be set by the owner of the IP address, not the owner of the domain. We have servers in 3 continents, and when approached each hosting company was able to help us set this. 2 had DIY tools, 1 had to set it for you. This website is great for telling you if you have a problem. http://www.mxtoolbox.com/ Put your site in, and then do an SMTP check. Regards, > Date: Fri, 19 Mar 2010 08:22:56 +0100 > From: [email protected] > To: [email protected] > Subject: Re: A lot of emails not reaching their destination, what can I do? > > > What I'm hoping for is simply some feedback and ideas. What can I do > to reduce this number? Is there something else I should do or check? > > Are you sure the helo name is the correct name? The helo name of an > email server should be equal to the reverse IP lookup. If not, a lot of > servers will flag the emails as spam. > > You can check the helo name using the following service: > > http://cbl.abuseat.org/helocheck.html > > (send an email to [email protected] with the system you want to > check, and a bounce message will show you the helo name) > > Pete Williams wrote: > > Hi > > > > First of all, I know this is not a James issue, but I don't know where to > > else to ask, and the responses might help others setting up an email server. > > > > James seems to be working perfectly well, however... > > > > A very high percentage of emails we send from James (say around a third) > > are not being delivered, for anti-spam reasons maybe. We are not spamming, > > BTW :) > > > > Here is the background that might be relevant. > > > > 1. Domain names are just a couple of weeks old. There are 3. > > > > 2. IP address is a reputable hosting company in each case: in the UK, US > > and Australia. > > > > 3. The emails are to help people sign-up for a trial software service > > they've asked for (ie, they've entered their name and email address for the > > trial into a web page). We are trying to send the sign-up info. No > > attachments are sent. One email is HTML, the second plain text. Both emails > > have URL links in them. > > > > 4. We have set-up the MX records ourselves and who knows, maybe we made a > > mistake? However, for the other 66% it works just fine. The domain name is > > set to the IP addr that the email comes from. > > > > For the emails not delivered, we frequently receive absolutely no response > > back - no bounce, nothing. Other times it's clear it's a spam issue, > > because the bounce back says so. > > > > I am not permitted to post the domain names on public forums, but if the > > admins want to check them out I can email privately. > > > > What I'm hoping for is simply some feedback and ideas. What can I do to > > reduce this number? Is there something else I should do or check? > > > > Cheers, > > > > > > > > _________________________________________________________________ > > Got a cool Hotmail story? Tell us now > > http://clk.atdmt.com/UKM/go/195013117/direct/01/ > > > -- > Djigzo open source email encryption > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > _________________________________________________________________ We want to hear all your funny, exciting and crazy Hotmail stories. Tell us now http://clk.atdmt.com/UKM/go/195013117/direct/01/
