[FEATURE] MMS support for email replies

[danry25]

What is the problem that this feature solves?
Our customer would like to send messages over 160 characters (or more than 70 characters when including unicode characters like emojis)

Describe the solution you'd like
Send messages longer than 160 characters (or more than 70 characters when including emojis) as MMS.

How will this improve revenue or reduce our costs?
This will retain an existing client and provide additional features for new clients, enabling a lower friction texting experience.