Name the email app and intended use
A signature is the block added to the end of an email. First identify the account and app where you want the logo to appear. Do not use a newsletter banner size as though it is the same task.
| Field | What to record |
|---|---|
| App | Gmail, the named Outlook version or another tool. |
| Account | The address that uses this signature. |
| Artwork | Full logo or an actually approved small variation. |
| Other content | Name, role and contact details beside it. |
| Destination | New messages, replies or both. |
Keep the approved source and prepare a copy for this purpose. If your business has signature rules, follow those before choosing a new arrangement.
Read the actual image guidance
Google recommends Gmail signature images 70 to 100 pixels high and 300 to 400 wide. It states a maximum of 100 high by 1000 wide. This is Gmail guidance, checked on 10 October 2026.
Sources for this point: Google signature image guide.
Do not stretch your mark to match both recommended dimensions. A tall badge and a long name have different proportions. Fit an appropriate copy to the client limits and inspect whether its complete wording still reads.
If you use another app, check that app's own instructions. These Gmail values are not a universal email standard. Keep the display size and original file size distinct in your notes.
Keep the mark in proportion
Classic Outlook for Windows offers Size and Lock aspect ratio.
Sources for this point: Microsoft Outlook signature guide.
For example, a 400 by 100 copy resized to a width of 300 has a height of 75. This is arithmetic, not a tested message. Your own dimensions may be different.
If a tagline becomes too small, consider more room or an approved variation. Do not remove words or squash the symbol without a decision.
Check the saved display rather than the upload alone
- View the intended signature in the message editor.
- Check the name, small marks and contact details together.
- Inspect a message on a wide screen and phone when available.
- Check for an unwanted background around the logo.
- If the logo has a link, confirm that it opens the intended destination.
You can send a private message to your own address to inspect the received view. That is a suggested check for you, not a message sent by this guide. A compose preview and a received view may answer different questions.
Keep a copy for email and a simple record
| Field | What to keep |
|---|---|
| Filename | The copy used for this signature. |
| App and account | The exact place where it is saved. |
| Display size | The width and height actually selected. |
| Check | The date and result if you perform the message check. |
If the image is too large or its small name is unclear, revisit the copy and display choice. Finish when the intended whole mark reads in the chosen signature and your actual message view. Keep the approved original for other uses.
Sources
These sources support the points linked above. Each date shows when we checked that source.
- Google signature image guide
Google gives Gmail image size and upload guidance Checked . - Microsoft Outlook signature guide
Classic Outlook offers locked image proportions Checked .