If you are having trouble replying to e-mails sent from a phone e-mail client just ask the sender to add their Full Name to their mail client’s settings. Note that the mail failure may look like this:

Hi. This is the qmail-send program at mailout-02-05.k12usa.internal.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

:

Rev=2.2.7, EXT=suzanned@k12hq.com<suzanned, HOST=k12hq.com, RECIPIENT=k12hq.com-suzanned@k12hq.com<suzanned@k12hq.com, SENDER=suzanned@k12hq.com, NEWSENDER=suzanned@k12hq.com, suzanned@k12hq.com<suzanned@k12hq.com not found bounced