cc flickr by marsupilami92

I have some good news for you. We have finally removed the problem that the Newsletter webservice has faced this summer.

This August, sending out the newsletter has been repeatedly delayed from 2 to 6 hours, which caused you a lot of trouble.

Greg, developer of the newsletter webservice, has identified the cause at the end of August, which helped us remove the problem. From now on newsletters are sent out as quickly as before.

This problem was caused by error emails. 

While sending out an email, our servers communicate with your recipients’ providers (yahoo, gmail, hotmail), and normally providers are terrified by error messages, because they cause a lot of useless work for them.
For example, for Yahoo, the more emails the server receives the longer it will take for the server to process your information. If the list of pending messages includes too many errors, processing can take a second, whereas the usual processing time comes to one millisecond.

This summer, we have repeatedly faced this challenge, when the newsletter has been sending error emails to the same server. Email processing was delayed, and as a result there were a lot of newsletters waiting in queue.
 

We’ve done 2 things to settle this problem:

1/Mixing of providers and emails.
From now on the queue consists of a list of emails that belong to different newsletters. Emails are classified  so that to avoid calling twice running for the same provider.

2/Scoring
We developed a scoring tool applied to the newsletters. This tool penalizes newsletters according to several criteria, as the number of error emails that it contains. If a newsletter has a bad score, the emails that it contains will be placed at the end of the list.

This system lets us get better results when sending out emails. Now we can allow again sending emails to hotmail accounts.