Differences between Fastmail and POBox?
 

I think this has been asked before, but are there major differences in the "back ends" between Fastmail and POBox.com (same company). For example, I noticed they use different nameservers.

Have a look here but may be a bit out of date now.

http://www.emaildiscussions.com/show...mail+OR+PO+Box

FastMail and Pobox use the same backend (originally from FM). The differences are mainly for historical reasons (before the takeover) to stay compatible.
See further: http://www.emaildiscussions.com/showthread.php?t=72615

Thanks--I even commented in those earlier threads about functionality, but I was thinking more about the "back end." Things like servers, DNS systems, engineers, etc. They seem to use different nameservers, indicating to me that the back ends are likely different. Not saying it is the case with POBox and FM, but with other providers I have tried there are often pretty dramatic differences in the performance of things like the web interface, speed of delivery, and even deliverability. Frankly, I'm rather surprised they haven't merged the two systems, taking the best features of both hopefully. It makes me wonder if POBox is going to be around much longer as it seems to have changed very little in several years, and obviously all the public facing activity seems to emanate from FM (blogs, news updates, etc.).

In 2016 Pobox services are moved to the datacenter of FastMail in NY. To what extent they have already been consolidated into 1 infrastructure is unknown to me.
Pobox is positioned as a forwarding service and FastMail as the email/calender service.
I think most of the users of Pobox has no Mailstore account (email inbox). That's what's FastMail is for.
Two of the eight staff members are formerly Pobox Inc. employees.

https://www.fastmail.com/about/company.html

I wouldn't know what percentage of customers on POBox use Mailstore, but it appears to be a much better deal than FM. POBox provides 50GB of storage for the same price FM provides 25GB. However, maybe FM's spam filtering is so much better it is worth it? I used to use POBoxes email forwarding, which worked well overall. It is a good solution I think for many people, but I found the spam filtering rather tedious to deal with. It required me to log into POBox way more than I wanted to.