How to Change an Email Signature and Its Logo

The short answer

To change an email signature, open the signature settings in your email client, edit the text, and replace the old logo image with a new one. The logo usually needs a separate step before that. A vector logo is built from mathematically defined paths, so it can scale to any size without losing sharpness. Many email clients do not display vector formats such as SVG reliably, though. For that reason, the vector master is normally exported to a raster image: a fixed grid of pixels, most often a PNG. The aim is a small, crisp, legible image made from the original vector artwork, inserted at a controlled display size and tested in the clients your recipients actually use.

What you need before you start

• Permission to use the logo. Brand ownership and usage rights decide whether you may use or alter it. The file format does not settle that.
• The approved master artwork, ideally in its native vector format or as an editable vector export.
• Confirmation that the master really is vector. Open it in a vector editor and check that the logo shapes can be selected as editable paths, not as one embedded picture. A file extension alone does not prove vector content or editability. For example, a PDF or EPS can contain only a pasted bitmap.
• Access to the signature settings for every account and device where the signature is used. Desktop, web and mobile apps may each store their own signature.
• Any brand guidelines on approved logo versions, colours and minimum sizes, if your organization has them.

Prepare the logo artwork

• 1. Choose the right version of the logo. Signatures display the logo small, so a compact horizontal lockup or a simplified mark often reads better than a full stacked logo with a tagline. A lockup is a fixed arrangement of symbol and wordmark.
• 2. Check the typography at small sizes. Thin strokes, fine serifs and small secondary text can blur or disappear when reduced. If the approved set includes a simplified small-size version, use that one.
• 3. Convert live text to outlines in a working copy, if the logo contains editable type. This turns letterforms into paths, so the export does not depend on fonts installed on your machine. Keep the original file with live text for future edits.
• 4. Clean up the geometry. Remove hidden or off-artboard objects, stray anchor points and empty groups. These can affect the exported bounds or add unwanted edges.
• 5. Fit the artboard tightly around the logo. The artboard is the export area. Leave only a deliberate, even margin, because extra empty space makes the logo look smaller and off-centre in the signature.
• 6. Use screen colour. Email is viewed on screens, so export in an RGB colour space, typically sRGB. Exports set up for print, such as CMYK, can shift in colour.
• 7. Decide how the logo should handle the background. PNG supports transparency. But if a client switches to dark mode, a transparent logo with dark artwork can become hard to see. Either test it against dark backgrounds or use a version designed to work on both light and dark.
• 8. Export a raster file larger than the size it will be shown at, for example twice the intended display width. This keeps it sharp on high-density screens. This is a design recommendation, not a documented requirement of any particular client.
• 9. Keep the file size modest by compressing the PNG without visible loss. Large images slow loading and may be flagged or clipped by some clients.
• 10. Give the file a clear name that identifies the brand and version, so it is not confused with older logos.

Change the signature in your email client

Menu names and options differ between email clients and between versions of the same client. No version-specific commands were supplied for this guide. Treat the steps below as the general sequence and check your client's current help documentation for the exact labels.

• 1. Open the client's settings or preferences and find the signature section.
• 2. Select the signature you want to change. If you keep several, such as for new messages and for replies, note which one is assigned to which.
• 3. Edit the text: name, role, contact details and any required legal lines.
• 4. Delete the old logo image. Confirm it is fully gone and not just hidden or left as an empty placeholder.
• 5. Insert the new image using the signature editor's image option. Depending on the client, the image may be uploaded and embedded in the message or loaded from a hosted address. Embedded images can appear as attachments in some clients. Hosted images may be blocked until the recipient allows remote content.
• 6. Set the displayed size if the editor allows it, so the larger exported file shows at your intended width.
• 7. Add alt text if the editor supports it, such as the company name. It is shown when images are blocked and is read by screen readers.
• 8. Save the signature and confirm it is assigned to new messages and, if wanted, replies and forwards.
• 9. Repeat the update on every device and app where the old signature is stored.

Confirm the result

• Send a test message to accounts you control in the email clients your recipients commonly use, including at least one desktop, one web and one mobile client.
• Check that the logo appears at the intended size, is sharp rather than blurry or jagged, and that small text in the logo is readable.
• View the message in dark mode where available and confirm the logo stays visible.
• Check whether the logo appears as a separate attachment, and whether it disappears when remote images are blocked. If so, confirm the alt text appears instead.
• Reply to and forward the test message to see whether the logo survives in a thread.
• Compare the colours against the approved brand colours on a standard screen.
• Confirm the old logo no longer appears on any device or app you updated.

Common problems and likely fixes

Problem | Likely cause | Fix

Logo looks blurry | Export was too small or was enlarged in the editor | Re-export from the vector master at a larger pixel size and set the display size down

Logo missing or broken icon | Client does not support the format, such as SVG, or remote images are blocked | Use a PNG; add alt text; check embedded versus hosted image behaviour

Logo vanishes in dark mode | Transparent background with dark artwork | Use a version that works on dark backgrounds or test an alternative

Logo shows as an attachment | Client embeds signature images | Check the client's options for inline images or a hosted image

Uneven spacing around logo | Artboard not fitted to the artwork | Trim the artboard to the logo plus an even margin and re-export

Wrong letterforms | Live text exported without the font | Outline the text in a working copy before exporting

Gaps to check for your setup

This guide has no verified specifications for particular email clients, such as exact menu paths, supported image formats, maximum file sizes or recommended pixel dimensions. Confirm these in your client's current documentation, and in your organization's brand guidelines where they exist, before finalizing the signature.