I've been watching this topic with interest, particularly as it mirrors some of what was discussed in an earlier topic entitled
PHP mail to external domains, with respect to problems with emails being deferred for hours/days by Yahoo's mail servers.
It seems little progress has been made and clearly, eUKhost have continued to try resolving this without much/any success. Corresponding with Yahoo has been a joke — personally, I'm not surprised it's still hopeless and I gave up weeks ago. I continue to have several accounts on my
Dedicated Server that have been suffering from Yahoo deferrals for weeks/months but the problem doesn't seem to be consistent or entirely predictable.
Anyway, the point of my interruption here is to open discussion about whether we can improve the Yahoo deferral problems by configuring the syntax of our SPF records in a certain way? I've been using SPF for a long time now and it doesn't appear to have helped much with regard to Yahoo, until recently ...
Additionally, I'd like to add that I haven't implemented Yahoo's recommendation of DomainKeys because I have been told by eUKhost that their experiments in implementing it were totally ineffective/unsuccessful (just in case anyone has an opposite opinion or experience)?
A couple of days ago I realised that the syntax of SPF records on my
Dedicated Server wasn't consistent, with some accounts managed by other resellers having no records, so I made changes on their behalf and after some thought, amended all the others ...
The majority of SPF records were in this format:
"v=spf1 a mx ~all"
...it would appear that Yahoo gives no preference to this. However, I changed my DNS Zone Templates to use this syntax:
"v=spf1 a mx ip4:%ip% ~all"
NOTE: that's a change to the template — if you modify each domain's SPF record manually, you substitute YOUR server's IP address for the ip4 placeholder, e.g.
"v=spf1 a mx ip4:111.112.011.012 ~all"
...here's a useful link for SPF Record Syntax.
After changing all the existing accounts manually, over a 48 hour period I've had no deferrals whatsoever!
OK, so it's too early to conclude that this is the solution but it's looking promising and I thought it would be better discussed now than in a week's time — it may transpire that all likely suspects for deferrals have sent nothing in last couple of days! I'm just interested to hear from anyone else who is experimenting with this or has alternative ideas? I'm particularly interested to know how eUKhost configure their default templates on shared servers etc? Do they differ or are they all using a common syntax?
And if this would be better discussed in a separate topic, I'll leave it to the moderators to sort out ...