I am using Sendgrid SMTP server for my emails on the default Mail cleint and I've set up the account on my HTC One android phone. The problem is it doesn't send emails, it keeps saying authentication failed. I've tried every combination of ports/ssl/tls and the same thing. My username/password is definitely right as I use it everywhere with no problem. I've contacted Sendgrid support but they can't figure out any problem with their servers so it may be just the way the Mail client communicates with their server. Other SMTP servers work fine on the phone, just Sendgrid doesn't.
Has anyone has problems like this with their outgoing mail servers?