I have had this issue since years, and with the database of customers growing, it becomes pretty important.
I have different customer groups (depending on their language they choose) and the mailing does only go through to a section of the users in the customer group chosen.
I have checked the email addresses if they have specific syntax errors. This manual process is also very time consuming. I have not found errors in the email addresses.
1. Why do I always get the message like
Your message has been successfully send to 190 of 253 recipients!
and the number of successful recipients change all the time. So, with the same recipients, in the first mailing, I will get a success with 170 and a second mailing was 190.
What is the reason.
2. Is there a way to check the email syntax and validity somehow with a script, for example a customer might have written their email addresses like this:
abc @live.com or
abc@ live.com or
I guess these errors might just make the mailing crash too.
3. How is the mailing organized: are the emails sent alphabetically or randomly or in another specific order. At least I will be able to find out up to which email address the mailing worked. I don't want to send emails twice to avoid stepping on the toes of customers.