Email Signature overlaps Email on iPhone 6S.

Are you using the stock Apple Mail app?

Can you perhaps take a screenshot of the issue and post it here, so we can better understand the issue?

How to take a screenshot on your iPhone, iPad, and iPod touch: https://support.apple.com/en-ca/HT200289

The cause of your text overlapping might be due to several settings in your iPhone. You may have changed this at some point without releasing or it may have been like that when you received the device.

There are several settings that you will need to look for and potentially change in order to resolve the issue.

1. Settings → Display & Brightness → Text Size → Move slider to center
2. Settings → Display & Brightness → View → Change it back to Standard
3. Settings → General → Accessibility → Larger Text → Larger Accessibility Sizes = OFF

I just tried some random forwards and replies and I don't seem to get that overlap. I even tried replying/forwarding a google notification email like the one in your screenshot.

Cheesy idea: did you try some hard carriage returns after the signature line to see if that helps?

Signatures can be tricky to get the formatting, font, size, etc. right. I was about to launch into a few tips but remembered that you also created some plain text ones (like in your screenshot), so I am baffled.

Last ditch thought: in Settings, Mail, is your "Increase Quote Level" (you have to scroll down a bit) set to ON? This is in the Composing section right above your signature. If not, try turning it on and see if it helps. If it's already on, there goes that idea hehe. Good luck.

Did you write "This is a test signature" four times in your signature (Settings → Mail → Signature) ?

Or did it replicate it 4 times?

One last setting I can think of: Settings → Mail → Load Remote Images = ON

Glad to see that after a year this is still an issue.

Did you ever find a solution? I have the same problem