Personalised from your directory
Sigil reads each person’s name, title, phone, address, department, manager and up to 15 custom attributes from Microsoft Graph, then stitches them into your template automatically, for every mailbox.
Every mailbox,
perfectly signed.
Sigil brings consistent, on-brand, always-current email signatures to every mailbox in Microsoft 365. Deploy it centrally, let it personalise every signature from your directory, and push a change in seconds.
✓ 14-day free trial✓ No card required✓ Deploys in minutes
ToPriya Sharma
SubjectRe: Q3 partnership proposal
Hi Priya,
Thanks for the quick turnaround. The revised terms look great. I've attached the updated deck and I'll get the agreement over to you shortly.
Best,
Alex
Alex Morgan
Head of Partnerships · Northwind Trading
M +44 7700 900321·E alex.morgan@northwind.co.uk
A 24 Kingsway, London WC2B 6NF
SecondsFrom publish to every mailbox
Read-onlyDirectory access, never write
One portalTemplates, rules, banners & analytics
£0.70Per mailbox / month, all-inclusive
Everything included
One place to control every signature
Marketing wants brand and campaigns. Legal wants disclaimers. IT owns deployment. Sigil gives each of them exactly what they need, all from a single web portal.
Design once, two ways
A block-based drag-and-drop designer for marketers, or a full HTML editor with placeholder autocomplete for power users. Both compile to Outlook-safe, table-based HTML that renders everywhere.
Rules that assign themselves
Ordered assignment rules pick the right template per person: by department, office, email domain or Entra group membership. First match wins; everyone else gets your org-wide default.
Campaign banners
Drop a time-boxed, clickable banner above or below every signature. It runs on your own time zone, stays DST-correct, and always tracks click-throughs. Open and close campaigns in a click.
Compliance footers
Append a mandatory legal block at render time, per email domain, so no template can ever forget the disclaimer Legal signed off on. Set it once and it’s always there.
Instant updates
Rebrand, fix a typo, or swap a disclaimer, then publish. The next message every user composes carries the change. There is no redeploy and nothing to touch on any machine.
How it works
A signature engine that lives inside Outlook
Sigil applies signatures client-side, as mail is composed. It never reroutes your mail flow or passes messages through a third-party server, and the cutover is invisible.
- 01
Deploy once, centrally
An admin grants Sigil admin consent and deploys the Outlook add-in through Microsoft 365 Integrated apps. Nothing gets installed on individual machines, and there is no per-user setup.
- 02
Users just write email
The add-in runs automatically on every new message, reply and forward, and again when a user switches the sending account. The user never clicks a thing.
- 03
Sigil renders in real time
It signs the user in silently with their Entra ID, reads their directory attributes from Microsoft Graph, and merges them into your active template: Outlook-safe HTML with inline images.
- 04
The signature appears
Sigil inserts the finished signature into the message and suppresses any local one. The user sees a correct, on-brand signature every time, with zero effort.
Microsoft-nativeEntra ID sign-in, Microsoft Graph personalisation, Office add-in. No third-party directory sync.
Windows, Mac, web & mobileAutomatic on Outlook for Windows, Mac and the web, plus Outlook for iOS and Android.
Cloudflare-fastRuns entirely on Cloudflare’s edge, so rendering is quick wherever your people are.
Prove it’s working
Finally know your signatures are actually landing
Traditional client-side signatures give you no feedback at all. Sigil closes the loop: every render and every apply is logged, so you can prove adoption across the whole organisation instead of just hoping for it.
- Per-mailbox activity: see who has applied their signature, and when.
- A never-applied list that surfaces mailboxes still missing their signature.
- An attribute coverage audit showing which directory fields are actually populated.
- An append-only change log of every admin action, for accountability.
Signature adoption Live
98.2%of mailboxes applied this week
98%
alex.morgan@ · applied · 2m ago
priya.sharma@ · applied · 4m ago
sam.lee@ · never applied
Security & privacy
Built to earn IT’s trust
Sigil is Microsoft-native and privacy-first by design. It never reroutes mail, never asks for write access, and holds no data you wouldn’t want us to.
Read-only, always
Sigil asks only for read access to your directory, never permission to send mail or write to your tenant. It reads what it needs to personalise a signature, and nothing more.
Strict tenant isolation
Every template, image and cache entry is scoped to your tenant. Each request must carry a valid Entra-verified user token, and there are no shared secrets in the add-in.
Privacy-respecting analytics
Link tracking counts clicks only. No IP addresses, no recipient identities and no message content are ever stored. You get the numbers without surveilling anyone.
Yours to govern
DSAR export and DPA tooling are built in, with published privacy, terms and support pages. Your data stays your data.
Pricing
Simple, per-seat, everything included
No tiers, no feature gates, no annual lock-in. One price per mailbox, covering every feature Sigil has, for everyone.
£0.70per mailbox / month
Billed monthly · cancel any time
Start your 14-day free trialReal seats from day one. No payment details required to start.
- Shared & resource mailboxes are free.
- Seat count is read from your directory automatically.
- Guests and disabled accounts are excluded.
Every plan includes
- Drag-and-drop & HTML template authoring
- Directory personalisation from Microsoft Graph
- Reply & forward signatures
- Assignment rules by department, office, domain & group
- Campaign banners & compliance footers
- Adoption, coverage & link analytics
- Drafts, versioning & one-click rollback
- Unlimited templates, admins & editors
Questions?
Frequently asked
Sigil applies signatures client-side, inside Outlook as you compose. It never rewrites your mail flow or routes messages through a third-party server. It deploys in minutes, changes take effect in seconds, and it can actually prove which mailboxes are getting their signature. Pricing is a flat £0.70 per mailbox per month with every feature included.
Once an admin deploys Sigil through Microsoft 365, the add-in runs automatically whenever a user composes, replies to or forwards a message. It signs the user in silently with their Entra ID, renders their personalised signature, and inserts it. There are no clicks and no setup, and the whole thing stays invisible to the end user.
From Microsoft Graph. Sigil reads each user’s directory attributes (name, job title, phone, address, department, manager and up to 15 custom extension attributes) with read-only access, and merges them into your template. Conditional sections automatically hide fields a user doesn’t have.
Template edits reach users in seconds. Publishing invalidates the cache, so the next message a user composes carries the new signature. There’s nothing to redeploy. Assignment-rule changes propagate within about 10 minutes.
Sigil applies automatically on Outlook for Windows, Mac and the web, and on Outlook for iOS and Android. It requires Microsoft 365 with Exchange Online, and event-based add-ins auto-launch once an admin deploys them centrally.
No. Because Sigil is client-side, the cutover is invisible and reversible. You can pilot it with a group first via assignment rules, then roll it out organisation-wide when you’re ready.
£0.70 per licensed mailbox per month, billed monthly, every feature included, cancel any time. Shared and resource mailboxes are free. Start with a 14-day free trial, with no payment details required and real seats from day one.
Sigil requests read-only directory access only, never permission to send mail or write to your tenant. Each tenant’s data is strictly isolated, no secrets live in the add-in, and link analytics count clicks only: no IP addresses, no recipient identities and no message content are ever stored.
Set up Sigil for your organisation
Consistent, on-brand signatures on every mailbox, deployed in minutes and updated in seconds. Start free and see it working across your tenant today.
14-day free trial · no card required · £0.70 per mailbox / month after