We have developed some CRM software which allows the users (our clients) to send emails to their clients (both individually and as a bulk email-out).
The emails are sent via our email server, but with the user's email set as the From address.
All emails are injected with an image tagged with a unique id that updates the database when the email is opened (assuming the image is downloaded).
ie img src='https://ourdomain.com/emailOpenedImage.jsp?id=0cb5a87f-3a35-11e0-8f64-11ac2edfd58d'/
We have taken the following steps to assist in ensuring that the messages are delivered:
- Throttling - the queue is paused every 200 messages.
- Reverse DNS - We have the IP address of the server registered to a domain.
We are also looking at the following, and I'm wondering if they will help.
- Domain toggling - if we send an email to say firstname.lastname@example.org, make sure the next few emails don't go to hotmail.com
- Changing the Sender Header - the From header and Reply-To Header will be set to, say, "John Smith (email@example.com)" while the Sender Header will be set to "John Smith(firstname.lastname@example.org)". Thus the email appears as "on behalf of".
So in a nutshell, given our situation, will Domain Toggling and Changing the Sender Header help (or hinder?) the chances of emails making it to the inbox?
And is there anything else we should be doing?
Any advice is much appreciated.