Many of the signature templates available within Signatures for Office 365 include images such as:
When it comes to uploading your own imagery into an email signature template, you must be aware of the following requirements.
When uploading any image, the file size should not exceed 150KB.
When an image is uploaded, it is:
- Automatically converted to 24bit PNG format.
- Resized to maintain the signature's aspect ratio.
Image screen resolution
We recommend that any email signature images you use are 96 dots per inch (dpi):