You have created your signature template with all the required information and images. Your initial email looks correct, but when viewing the email in Apple Mail, either on the desktop or on a mobile device and tablet, the image overlays part of the signature, banner, or social icons like on the screenshots below.
This has been a well-known issue by the Apple community for ~2 years; please check this article for more information. Unfortunately, it has not been officially fixed yet, but there are some workarounds, which you might find below.
1). Ensure that the images used within your signature design are created at the required size for the signature template.
Apple Mail Client is trying to use the Width and Height values set on the image(s) in the signature template while reverting the image(s) to the Native image size. Sometimes this can occur when sending an email from a mobile device and viewed on an Apple Mac or Tablet.
We recommend uploading a logo/personal image as a .png file with a high resolution and high DPI (300). For example, if your logo appears as a 150x150 image in the signature, then a 450x450 image must be uploaded; what's more important - the image's resolution should be divisible by 2, 5, and 10, for example, 200x200 or any other round numbers, and the banner-image keeping the ratio 1:5 or 1:6. It is strongly recommended to use a high-quality image. More importantly, the image's resolution should be divisible by 2, 5, and 10; for example, banners from the gallery are 1000x200 pixels.
2). Please follow these simple steps to reinstall your signature on your iPhone/iPad:
- Go to your Mail settings on your iPhone.
- Open Signature. Click Per account. Paste the signature to each account individually.
- Please do the Shake and Undo.
3). Please check the following settings on your iPhone and potentially change them to resolve the issue:
- Settings → Display & Brightness → Text Size → Move slider to center
- Settings → Display & Brightness → View → Change it back to Standard
- Settings → General → Accessibility → Larger Text → Larger Accessibility Sizes = OFF