Still can't send mail on my iPhone. I keep getting the message. It appears about 15 to 20 minutes after attempting to send an email:
"The connection to the outgoing server xxxx failed." The xxxx shows an actual smtp server IP address, but I will not share that here. That server, BTW, is located somewhere else and is most likely controlled by Apple or one of their service providers.
So, I can receive (some/all?) email on my iPhone, but I cannot reply to any. I also cannot access emails older than a few weeks -- an iCloud cache problem, perhaps. On my iMac, I cannot receive or access any iCloud services via Safari. As nothing changed with our hardware setups since we went to bed last night, it is clearly external to our domain and beyond our control.
It is not possible to conduct business without these services. It's hard to run your startup without some key tools! Whereas I've experinced a few hours of iCloud downtime before, this has been the longest downtime to date -- going on eight hours. I guess it is time to contact support.