SMS signature support

[user-1-2-3-4-5]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the request will be dismissed otherwise.
• This issue contains only one feature request.
• I have read and understood the contribution guidelines.

Feature description

Fossify Messages has no support for the sender signature, which is a common feature in SMS and email applications.

The signature typically appears on a new line at the end of the message.

Why do you want this feature?

Many prefer signing their messages with their full name, possibly supported by workplace-related information, to avoid confusion. Using a template is essential to eliminate any chance of typos especially with longer signatures.

Additional information

No response