Marketing · Banners
Email signature banners: marketing in every email
An email signature banner is a clickable image, usually up to 600 pixels wide, placed under your signature to promote one thing: an event, a product, a case study, a review page or a job opening. Email signature marketing is using that space deliberately, and measuring what it brings in.
By the Regardly team Updated 5 min read
In short,
- One banner, one message, one action. Link it to a page made for that message.
- Show it at up to 600 × 100–150 px, upload it at twice that size, and keep it light.
- Measure clicks (reliable) rather than views (an estimate, like opens).
- Use a banner you can change later without re-pasting, so campaigns can start and stop on a date.
- Leave the banner off replies in long threads, support conversations and sensitive emails.
On this page
Why a banner in your signature
Most marketing channels fight for attention from strangers. Your signature reaches people who already talk to you: clients, prospects, partners, suppliers. They open your emails because they're expecting them. A banner under your name puts one relevant message in front of that audience, without an extra send, ad budget or newsletter list.
That's also why it has to be relevant. A banner nobody cares about is noise in an email that matters to the reader. The goal is a small, useful nudge.
What to promote
| Goal | Banner example | Link to |
|---|---|---|
| Event or webinar | “Live demo, 12 March. Save your seat” | Registration page |
| Launch | “New: the spring collection is in” | Product or launch page |
| Social proof | “How we helped a client halve their processing time” | Case study |
| Reviews | “Happy with us? Leave a review” | Your review page |
| Hiring | “We're hiring developers” | Jobs page |
| Practical | “Closed 24–26 December” | Opening hours page |
| Meetings | “Book 15 minutes with me” | Booking page |
Designing a banner that works
- Size: display it at most 600 px wide and about 100–150 px high, and upload it at 2× (1200 × 200–300 px) so it stays sharp. More in signature size and images.
- One message: a short headline and a clear action, readable on a phone where the banner shrinks to half its width.
- Text size: no tiny print. If it's not readable at 300 px wide, it's too small.
- Alt text: write the message itself, because some apps block images until the reader allows them.
- Brand, not noise: your colours, plenty of space, and no fake buttons that look like system messages.
- Light file: a JPG or PNG of tens of kilobytes. Animated GIFs only show their first frame in classic Outlook for Windows.
Run it as a campaign, not a permanent fixture
A banner that never changes becomes invisible to the people you email most. Treat it as a campaign: a start date, an end date and one goal. That only works if you can change the banner without asking everyone to paste a new signature.
That's how Regardly does it: the banner in your signature is a hosted image and a tracked link on go.regardly.app. Once your tracked signature includes a banner, you choose in your dashboard which campaign it shows and when, and the signature you already installed shows the current banner from then on. Emails you sent earlier can show the new banner too when their images are loaded again, although some mail apps keep a cached copy. When the campaign ends, the banner goes. On the Team plan you run campaigns centrally for everyone.
Measuring results
Three numbers matter:
- Clicks: the most reliable signal. A tracked link counts each click, and known security scanners are filtered out.
- Views: how often the banner image was loaded. Like email opens, this is an estimate: Apple Mail can preload images and other apps block them. See why opens are estimates.
- Click-through rate: clicks divided by views. Useful to compare banners with each other, less useful as an absolute number.
For what happens after the click, add UTM parameters to the destination URL (for example ?utm_source=email-signature&utm_campaign=webinar-march) so your website analytics show signature traffic separately.
A/B testing banners
With two variants of a banner you can learn which message or design gets more clicks. Regardly rotates variants by week: every email in the same week shows the same variant, so the image someone sees and the link they click always match. Some tips:
- Change one thing per test: the headline, the image or the call-to-action.
- Run it long enough to cover a few weeks per variant, so a busy week or a holiday doesn't decide the result.
- Look at clicks, not just click-through rate. A handful of clicks isn't a winner yet.
When to leave the banner out
- Replies in long threads. Ten copies of the same banner in one conversation is clutter. Gmail and Outlook let you use a shorter signature for replies and forwards.
- Support and complaint emails. A promotion next to a problem reads badly.
- Sensitive conversations: HR, legal, medical, bad news.
- Image-only signatures. Keep your contact details as text, with the banner as an addition. Emails that are mostly one big image look like bulk mail to spam filters and to people.
Start your first banner
- Make your signature, or pick a template with room for a banner, like Bold Banner or Hero Card.
- Design one banner for one goal, 1200 × 250 px, with the message in the alt text.
- In Pro, create a campaign with a start and end date, and optionally a second variant to test.
- Copy the tracked signature, paste it with the install guide and check your clicks after a week.
FAQ
Frequently asked questions
What size should an email signature banner be?
Display it at most 600 pixels wide and about 100–150 pixels high. Upload it at twice that size, for example 1200 × 250 pixels, so it stays sharp on high-density screens.
Can I change my signature banner without everyone re-pasting their signature?
Yes, if the banner is a hosted image with a tracked link, like in Regardly Pro and Team. You change the campaign in the dashboard, and the signature that's already installed shows the new banner.
Do signature banners hurt deliverability?
One modest, light image under a text signature is normal in business email. Problems start with image-only emails, very heavy images or many images. Keep your contact details as text.
How do I measure if my signature banner works?
Count clicks with a tracked link, compare click-through rates between banners, and tag the destination URL with UTM parameters so your analytics show what visitors do next.