Hello Wietse, I was reading this topic with interest because this issue affects me very much as well.
I had a slowness issue when sending to @hotmail.* . I tried all the Microsoft services in order to check how I was seen from them and I got confirmation that I was OK. I received this information not only through MS SNDS[1] but also agreeing a sending window with one of their engineers who observed my actual sending and investigated evidence of troubles. During a massive sending I was able to complete all destinations in 1hour BUT Microsoft's. (and Apple's) By looking at my logs I was capable of noticing they were slowly accepting my TCP requests, or, said better, slowing down everything related to the connection establishment. To complete my sending to @hotmail.* I was spending more than 12 hours... I changed my client configuration, for that dedicated transport, disabling STARTTLS support and so making effectively use of the connection cache. y using the connection cache I managed to get that sending complete in approx 1hour. I then applied the same configuration for Apple domains and a couple of local national ISPs. I could afford to proceed like that because: 1. these emails are just marketing 2. those mailbox providers are not providing evidence to the end user that the email was sent in clear text instead of TLS-secured. Were they to do the same as Gmail does, the red lock to email received in plain text, I will need to revert my configuration and eventually get my sending slow again... Thank you in advance for everything you can develop in order to overcome this limitation. Marco P.s. As a side note: the second limitation I face in using Postfix for bulk email sending is the missing "MX-rollup" feature I already reported twice in this list: http://postfix.1071664.n5.nabble.com/Feature-request-MX-rollup-td90800.html [1] https://postmaster.live.com/snds/ <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virus-free. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#m_6573517841975336091_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> On Mon, Mar 19, 2018 at 4:28 PM, Wietse Venema <[email protected]> wrote: > Emmanuel Fust?: > > Is there any document that describe how interprocess notification is > > done in postfix ? More precisely the scheduler -> delivery agent > > notification ? > > There is no public documentation for *internal* Postfix interfaces, > so that I can change that without breaking non-Postfix software > that depends on Postfix internals. > > I agree with Viktor that updating the TLS proxy is the more feasible > approach (caching the TLS sessions outside delivery agents). I also > don't believe in changing the scheduler-to-delivery agent protocol. > The Postfix approach is not to make an existing thing more complex, > but by combining less complex things together. > > Please provide quantitative evidence that connection reuse is > necessary to get mail into the 'big providers' (i.e. they punish > connection rate and message rate differently). > > Wietse >
