2.2 upgrade poots a SMTP connection?

Question

Prior to upgrade had an IMAP/SMTP account working great. Do upgrade, can't send SMTP mail.
This exact account worked fine with the same config, on same Wifi connection, just before the upgrade.
IMAP retrieval works fine.
Can test IMAP/SMTP on same account via a PC (outlook) client and same 'old' settings seem to work fine. In fact I can create a brand new IMAP/SMTP account on a PC in 15 seconds and it works perfectly - all working on same Wifi network. Yet when I do exact same settings / network from iPhone, no joy.
I happen to be the admin for that server so I can look at the server logs and don't see the iPhone authenticating as a user to that server... there seems to be a long delay before I even see a trace of TCP/IP connection from it. I suspect it's sending some weird username/PW format that slightly changed with 2.2 but of course can't tell exactly.
Another POP/SMTP on the iPhone works exactly fine post upgrade - aka I can send/receive from that account no problem.
Stuff tried: server reboots / server config checks / previously mentioned pre-existing and brand-new outlook client setups / alternate DNS hostnames for same server / rebooting / deleting entire account and re-setting up on iphone / 'forgetting' the Wifi network on iPhone and starting over / etc. etc.
Anybody else getting problems with the new 2.2 and SMTP connections? Server is a Lotus IBM Domino (I know somebody will say "lotus suxz" but it has worked w/ lots of iphones for the last year, as well as Nokia/Blackberry/PC/etc/etc for many years.)

Answer 1

Well I found that the SAME SMTP settings, now WILL work fine over 3G. Which is weird as of course Wifi vs. 3G should theoretically be invisible to an IP application like email.
With WIFI it does matter where you are. At home, of course, you expect it to work the same as your computer, but traveling or in coffee shops its not uncommon to find blocked smtp ports, and your ISP generally will not allow sending mail from outside their own network.
So one possible failure scenario is that sending fails on WIFI because it tries your ISP, and they say NOWAY, so it goes to the next SMPT, which in many cases is your carrier's SMTP server (ATT's smtp server) and it says NOWAY since you didn't arrive via their network (didn't send via cellular network).
On 3G (or edge) this server of last resort (ATT smtp server) would succeed.
For Authenticated Connections (over ssl for example) this SHOULD work on WIFI.
But I don't think cwmx.com (ATTs smtp server) will accept authenticated connections from other than it's own network, and even if it did, it runs on port 25, which is often blocked by wifi hotspots, or blocked by your ISP, and even if it wasn't blocked, its un-connectible via WIFI. ("telnet cwmx.com 25" will always fail, even tho cwmx.com resolves).
So what has changed to cause 2.2 to fail where this always seemed to work on 2.1?
Don't know, but maybe in the process of finding an smtp server, the TCP stack does not try other network connections (routes). If connecting via wifi fails, perhaps it never tries those same destinations via Edge/3G for example.
This is not atypical of TCP stacks. If they get a positive TCP/IP connectivity, (even one that results in an emphatic denial of service) its unusual for them to try that SAME connection via different network interface.
ATT's SMTP server should support SSL, but it seems not to, or at least the settings iphone do not indicate anything other than port 25. Therefore the SMTP server of last resort is never available via wifi.
My recommendation: Get a gmail account, and configure it as an alternate SMTP server for ALL email accounts. It always works.