Mandrill XoDrill and Hotmail spam issue solved ?

I’m a Mandrill user for quite a long time (using SMTP) and have issues sending mails to Hotmail addresses, only hotmail addresses, most of the messages being placed in the Spam folder.

The Mandrill DKIM and SPF settings of the sending domains are correct, tested and verified.

I tried XoDrill classes using JSON (@scott boss) classes and gave it a try… But still had the same issue.

I found some info on the web saying that it could be caused by missing reply-to address.

I added a reply-to address in the message header and now all message are coming into the Inboxes !

Here is how I changed XoDrillMessage class:

  • added a Property replyToEMAIL (String) in
  • added a few lines in the BuildMessage method to add a reply address (same as the sender’s address)
' --> lines, added before the «tags» handling in BuildMessage:
' add reply-to address (use fromAddress if reply-to missing)
  if replyToEMAIL.len   = 0 and fromEMAIL.len > 0 then  
    replyToEMAIL = fromEMAIL
  end if
  if replyToEMAIL.len   > 0 then
    dim jsonReply as new JSONItem
    jsonReply.Value( "Reply-To" ) = replyToEMAIL
    jsonMessage.Value( "headers" ) = jsonReply
  end if

I’m not sure it will solves 100% of the hotmail issues but for me it’s > 90% improvement.

XoDrill classes are much nicer and more complete than my previous coding using SMTP, thanks Scott !!!

@Olivier Colard I am you are liking/enjoying the XoDrill classes.

I will add the replyto to the buildMessage in the next release. If there is anything you would like me to add sooner than later, please let me know. I have been adding things in a semi-random order.

Hey Scott,

Sorry for replying so late, I was out of business for a few days.
Sorry also to say that the hotmail problem is not solved. It was better as I received a bunch of mails in my hotmail test address but testing again yesterday and today I received a few in the inbox and many in spam box.

My app is an automated reservation systems for events and most customers with hotmail addresses were complaining.
All mails are almost identical, but for a few variables (date, nbr of places) and of course the address.

I’m looking at the source of the mail but can’t see any reason some are accepted and others considered as spam.

Any idea is welcome !

I can provide sources of pass/fail messages…

Still don’t understand:

  • I moved back to my SMTP classes and messages are now coming into the inbox
  • Tried adding Reply-To in SMTP Header … BANG, message in spam folder
  • Removed the reply-to address for SMTP and thy are back in Inbox

So, I changed back the XoDrill and removed Reply-To … message arrives now in Inbox

I don’t know what’s happening, I can’t change my settings every day.
Yesterday the Reply-To was solving (sometimes) the issue, today I have to remove it.

As there are no errors I have no way to know if the message arrived.

Before writing my own app I used Jotform.
Jotform messages were always delivered correctly, even for Hotmail addresses.
I made a test again with Jotform and it’s fine for Hotmail.
Looking a their source, I see no SPF, no DKIM, no reply-to address …

I’ll do more tests with SMTP and JSON without Reply-To to see if this is reliable for a few days.

let me know. but based on what you have said, it seems the issue is between Mandrill API and Hotmail not the XoDrill classes themselves.

Hi Scott,

I never had the impression that XoDrill was the issue as I had the same problem with my own SMTP classes.

I finally found an answer and all tests since then are positive, all messages being delivered in the Inboxes.
There was a small typo in the HTML meta-tags (http-equiv) that didn’t make a difference when displaying the messages, but seems to be unacceptable for Hotmail (accepted by gmail, yahoo).

The messages are delivered with or without reply-to addresses.

Thanks anyway !