Today I had the issue on a customer site that no iOS device was able to send mail after upgrading Traveler to 10.0.1.2 on Domino 9.0.1 FP10IF3, implementing a new wildcard certificate and reconfiguring the HTTP server to redirect HTTP calls to HTTPs.
After some investigation I checked the console log and discovered multiple error messages:
[12DC:000C-0FEC] 10.12.2019 08:39:06 Traveler: WARNING username´s Request is empty and command SendMail is expected to have a body.
After rechecking the server document of the Notes Traveler server I checked the entry for the external URL >> http://servername.company.com. So the company did not use SSL certificates for the communication of mobile devices with their Traveler !!! Therefore no NOTES.INI entry called “NTS_EXTERNAL_URL=https://….” was set.
A small correction of the entry in the server document, setting the NOTES.INI entry via “set configuration NTS_EXTERNAL_URL=https://servername.company.com UPDATE” and a restart of the Traveler service was only half the way.
If you have this configuration of configured profiles on iOS devices WITHOUT SSL ( hopefully no one is using this anymore ) you have to remove and recreate the profile because you can´t modify the account to use SSL !