A good email signature takes less than a minute to read and tells the recipient everything they need. A bad one quotes Marcus Aurelius, plays an animation, and still manages to have the wrong phone number. Here are ten rules that separate the two.
Build a signature that follows every rule →
Rule 1: Keep it to 4–6 lines maximum
The signature exists to give people a way to reach you — not to summarise your career. Four to six lines is the sweet spot: enough to include your name, title, company, phone, and a link or two. Beyond that you are adding noise to every email you send.
If you find yourself writing a seventh line, ask whether the information is genuinely useful to someone who just received an email from you, or whether you are padding it out of habit. Cut the padding.
For context on how signature height maps to rendering across different email clients, see the email signature size guide.
Rule 2: Include only contact information that is actually useful
Your direct phone number and website belong in your signature. Your fax number, your office extension that goes to a voicemail nobody checks, and your mailing address (unless clients need to send you physical post) do not.
Apply a simple test: if a recipient needed to reach you urgently, which of these contact details would they actually use? Keep those. Remove the rest. A signature with three contact methods that all work is more useful than one with six that are hit-and-miss.
For more on choosing the right elements, see the professional tips guide.
Rule 3: Remove inspirational quotes
This one is worth stating plainly: inspirational quotes in email signatures do not land the way their authors intended. A recipient receiving a billing dispute, a project delay, or a piece of bad news does not benefit from "Dream big. Work hard. Stay focused."
Quotes age badly. They often feel off-brand. And they add a line of text that serves no functional purpose. If your organisation has a mission statement or tagline, use that sparingly — but even then, consider whether every outbound email is the right vehicle for it.
The best practices guide covers this and other common signature mistakes in more detail.
Rule 4: Use consistent formatting across your team
When ten people at the same company have ten different signature styles — different fonts, different layouts, different colour schemes — the cumulative impression is one of disorganisation. Recipients who deal with multiple people from your organisation will notice the inconsistency before your team does.
Consistency does not require everyone to have identical signatures. Job titles, direct phone numbers, and social links will vary. What should stay consistent is the layout structure, the font, the colour choices, and the logo. A shared template handles this automatically.
If you are setting this up for a team, use an email signature generator that allows you to create a master template and populate individual details — rather than asking each person to build their own and hoping they follow guidelines.
Rule 5: No animated GIFs
An animated GIF in an email signature is never as clever as it seems in the moment. In Outlook — which a large portion of business email still runs on — animated GIFs render as a static image anyway, usually the first frame, which is rarely the one that makes sense on its own. In clients that do render the animation, the movement is distracting during the thirty seconds someone spends reading your actual message.
If you want a visual element in your signature, use a static banner or a professional photo. Both communicate more than a looping animation and work across every major email client. See Rule 7 and Rule 6 respectively.
Rule 6: One CTA maximum — booking link, banner, or social, not all three
A call to action in your signature is legitimate. A booking link that gets you straight into meetings, a promotional banner for a product launch, or a LinkedIn icon — any of these works. All three together turn your signature into a marketing sidebar that competes with your actual email for attention.
Pick the one that serves your current goal. If you are in a sales role, a booking link is probably more valuable than a Twitter icon. If you are mid-campaign, a banner makes sense. If neither applies, two or three social links are enough.
Treat it as a single slot. When your goal changes, rotate what is in that slot. The banner feature guide shows how to add and update a promotional banner without rebuilding your signature from scratch.
Rule 7: Use a professional photo — or none at all
A headshot in an email signature increases reply rates, builds trust faster than any line of text, and is particularly effective for client-facing roles. But the keyword is professional. A cropped party photo, a photo taken in poor lighting, or one where you are visibly mid-blink are worse than no photo.
If you have a clean, professional headshot with a neutral or simple background, use it. If you do not have one yet, leave the photo slot empty until you do. A blank space is far better than a photo that undermines your credibility.
See email signature with photo for sizing guidelines and live examples of how different photo styles render across email clients.
Rule 8: Keep font sizes readable — 10px minimum, 14px for your name
Email signatures are already small by nature. Shrinking the font to 8px or 9px to fit more information in the same space creates a signature that technically contains everything but cannot be read without effort — particularly on mobile.
The practical baseline: 10–11px for secondary information (phone, website, legal disclaimer), 12–13px for your job title and company, and 14px for your name. Your name is the anchor of the whole thing — it should be the most readable element, not the smallest.
For a complete breakdown of sizing by element type and device, the email signature size guide covers everything with specific numbers.
Rule 9: Remove "Sent from my iPhone" from mobile
The default mobile signature is turned on by default, which is why so many people still have it. It takes about forty-five seconds to remove. There is no professional reason to advertise your device manufacturer in every email you send, and there is a reasonable argument that it signals — fairly or not — that you did not invest any thought in your outgoing communications.
On iOS: Settings → Mail → Signature → delete the default text and replace it with your actual signature or a plain-text version of it. On Android, the path is similar within your mail app's settings. If you use a mobile email app like Spark or Airmail, the signature settings are usually in the account preferences.
Rule 10: Keep your signature current — outdated info is worse than no signature
A signature with the wrong phone number wastes the recipient's time. A signature with your previous company's name is actively confusing. A signature pointing to a dead website makes you look careless. Outdated contact information is probably the most common email signature problem there is, and it is entirely avoidable.
Any time your job title, company, phone number, website, or social handles change, update your signature the same day. Set a calendar reminder to review it once per quarter regardless. If you built it with a generator, updating it takes a few minutes and produces clean, tested HTML that you can paste straight into your email client.
What these rules mean for teams vs. individuals
Most of the ten rules above apply equally whether you are managing your own signature or rolling out signatures for a 50-person team. But scale changes a few things worth knowing about.
For individuals, the biggest risk is neglect. A signature you built three years ago with an old title and a phone number you no longer have is doing damage you may not notice. Audit it now. The best practices guide has a quick checklist.
For teams, the biggest risk is inconsistency combined with no clear owner. When everyone builds their own signature and there is no template, you end up with a range of styles, some outdated, some with fonts that break in Outlook, some with no logo. The fix is a shared template controlled by one person — typically someone in marketing or IT — with individual fields populated per person.
Teams also need a rollout plan for Rule 10. When the company rebrands, the office phone changes, or a new CTA goes live, someone needs to push updated signatures to everyone. An email signature generator that supports team management makes this a single update rather than a company-wide announcement followed by weeks of chasing.
FAQ
How many lines should a professional email signature have?
Four to six lines is the standard. That is enough space for your name, title, company, phone number, and one or two links. Signatures longer than six lines begin to compete with the email body for attention.
Is it unprofessional to have a quote in your email signature?
Yes, in most professional contexts. Inspirational quotes do not add contact information and can feel tone-deaf depending on the email's subject. A company tagline or campaign line is a borderline case — use it only if it is brief and has a clear professional purpose.
Can I have more than one CTA in my email signature?
Technically yes, but practically no. Two or three CTAs compete with each other and reduce the likelihood that any of them get clicked. One clear, relevant CTA — whether a booking link, a promotional banner, or a social icon — performs better than a row of competing options.
Does the "Sent from my iPhone" disclaimer matter?
It matters more than most people realise. It signals that you have not customised your mobile email setup, which carries a subtle implication about attention to detail. It takes less than a minute to remove it. Remove it.
How often should I update my email signature?
Immediately after any change to your title, company, phone number, or website — and at a minimum once every quarter as a routine check. Outdated signatures are one of the most common and most avoidable credibility problems in professional email.