CodeTwo Alternatives in 2026: Email Signature Tools by What You Need

By David, 2026-11-09, updated 2026-11-09

The main CodeTwo alternatives are Exclaimer, Crossware, Opensense, Letsignit, WiseStamp, Rocketseed and Atlas Ink, with Exchange Online mail flow rules as the free built-in option. Which one fits depends on why you're leaving CodeTwo: you need Google Workspace or HCL Domino as well as Microsoft 365, you want deeper campaigns, you don't want outbound mail relayed through any vendor, or you want to pay only for the users who actually carry a signature.

The short version: For Google Workspace as well as Microsoft 365, look at Exclaimer, Crossware, Opensense, WiseStamp or Rocketseed. For CRM-linked campaigns, Opensense. For no vendor relay, an Outlook add-in such as Letsignit, or Atlas Ink, which writes signatures into the mailbox from your own Azure subscription. For metered pricing on Microsoft 365, Atlas Ink. For a plain legal footer, Exchange Online mail flow rules.

What CodeTwo does

CodeTwo Email Signatures 365 is a cloud service for Microsoft 365. Its server-side mode routes outbound mail through CodeTwo services hosted on Azure, adds the signature, and hands the message back for delivery; CodeTwo says your emails never leave Microsoft datacenters, and you can keep your settings in an Azure region you choose. Its Outlook add-in inserts the signature while you write, in Outlook for Windows, Mac, the web, iOS and Android. You can run either mode or both. Rules work on Entra ID attributes, sender, recipient or keywords, and it also handles disclaimers, auto-replies and scheduled campaigns, with signatures visible in Sent Items.

For Exchange Server, CodeTwo sells a separate product, Email Signatures On-prem, which runs entirely on your own servers. It succeeds CodeTwo Exchange Rules, which is retired.

So CodeTwo covers a lot. The reasons teams look elsewhere are usually specific, and each one points to a different shortlist.

If you also run Google Workspace

CodeTwo Email Signatures 365 is built for Microsoft 365. CodeTwo said in 2024 that it was working on Google Workspace support, but we found no launch on its own site as of November 2026. These tools name both platforms:

• Exclaimer signs mail server-side for Microsoft 365, Google Workspace and Exchange, with an Outlook add-in, campaigns and analytics. Its datacenter region is assigned by geolookup.
• Crossware applies signatures server-side across Microsoft 365, Google Workspace, Exchange and HCL Domino, from Microsoft datacenters. It's the one to look at if Domino is still in the estate.
• Opensense covers Microsoft 365 and Google Workspace, through an Exchange Online transport rule, an Outlook add-in, or the Gmail API.
• WiseStamp and Rocketseed both cover Microsoft 365, Google Workspace and Exchange. WiseStamp offers server-side, add-in, extension and desktop-app options; Rocketseed is server-side only.

Check: whether each vendor supports every feature you use on both platforms, not just "Google Workspace" in general.

If you want deeper campaigns

CodeTwo has scheduled campaigns with URL tagging for analytics. If marketing wants more than that:

• Opensense links banners to HubSpot, Salesforce or Marketo and reports impressions, clicks and click-through rate. It also supports GCC High.
• Exclaimer offers campaigns and native analytics across Microsoft 365 and Google Workspace.
• Rocketseed offers targeted banners with A/B testing and a Google Analytics integration.
• Letsignit and WiseStamp both offer campaigns and click analytics; WiseStamp adds rotating banners and surveys.

Our Letsignit, Opensense and WiseStamp field map compares three of these in more depth.

If outbound mail can't be relayed through a vendor

Server-side stamping, CodeTwo's included, means a third-party service handles every external message, even when that service runs inside Microsoft's datacenters. If your security review wants no vendor relay at all, there are two other ways to get a managed signature onto mail:

• An Outlook add-in inserts the signature while the user writes. Letsignit is add-in first and says email content doesn't pass through its servers, with hosting in the EU on Azure. CodeTwo's own add-in mode, used on its own, works the same way. The catch is coverage: the add-in has to be deployed and running in every client your people use.
• A mailbox signature is written into each user's mailbox, so Outlook adds it itself. That's how Atlas Ink works, and it's covered below.

The server-side vs client-side explainer walks through each model's trade-offs in detail.

Atlas Ink

Atlas Ink is our product, so weigh this section accordingly. It's built for the case where IT owns the signature and the tenant is Microsoft 365:

• It runs in your own Azure subscription. The App Service, the per-tenant PostgreSQL database and the Key Vault keys are yours. It reads Entra ID read-only. No signature content leaves your tenant: Atlas receives an active-user count for billing and, if you use banners, the banner links and their click counts.
• It never routes mail through Atlas. It writes each user's signature into their mailbox through the Exchange admin API, so it appears while they write in Outlook on the web, new Outlook for Windows and Mac, and Outlook for iOS and Android, on new mail and on replies.
• Classic Outlook and other clients are opt-in. Classic desktop Outlook and non-Outlook apps don't read the mailbox signature. For those users you can turn on server-side stamping: one mail-flow rule in your own Exchange Online that Atlas configures but never sits in. It needs explicit admin consent and the Exchange Administrator role, and it isn't available in GCC or GCC High.
• It enforces. Templates are assigned by tenant, group or user, with the most specific winning. A daily reconcile puts back a signature someone edited or cleared, and you get per-user rollout status, revision history and rollback.
• It's metered. $1 per active user per month, prepaid in units and billed via Stripe, counting only users whose mailbox carried a managed signature that month. It runs standalone on the free Community plan.

Here's the analytics view in our demo environment, with coverage and drift over time. It's the real Atlas Ink console; the users are sample data:

Choose it over CodeTwo when: you want managed signatures on Microsoft 365 with no vendor in the mail path, the platform inside your own Azure tenant, and a bill that tracks active users. Check: it doesn't support Google Workspace or on-premises Exchange, Outlook roaming signatures must be turned off in the tenant, and it doesn't do auto-replies or CRM-linked campaigns. The Atlas Ink vs CodeTwo comparison sets the two side by side.

If you only need a legal footer

Exchange Online mail flow rules can append HTML or plain text to every message, with sender details such as name, title and phone filled in from the directory, at no extra cost. Microsoft's own documentation lists the limits: the text can't go directly under the latest reply, senders don't see it in Sent Items, images have to be linked rather than embedded, and you need an exception to stop it repeating down a thread. It's a good fit for a mandatory footer and a poor one for a designed signature. Our legal requirements by country guide lists what that footer has to contain.

CodeTwo alternatives at a glance

How to move off CodeTwo

1. Export your signature templates and rules, and list any disclaimers, auto-replies and campaigns you'd need to rebuild.
2. Record the Exchange Online connectors and rules CodeTwo's server-side mode uses, and which users have its add-in.
3. Pilot the new tool with a small group, checking new mail, replies and forwards in every client, phones included.
4. Move group by group, turning CodeTwo off for each group as you go so nobody gets two signatures.
5. Remove the connectors, rules and add-in once the last group has moved.

FAQ

What is the best alternative to CodeTwo?

It depends on why you're switching. For Microsoft 365 plus Google Workspace, look at Exclaimer, Crossware or Opensense; for CRM-linked campaigns, Opensense; for an add-in with EU hosting, Letsignit; and for IT-owned signatures that stay inside your own Microsoft 365 and Azure tenant with no vendor in the mail path, Atlas Ink.

Does CodeTwo support Google Workspace?

CodeTwo Email Signatures 365 is built for Microsoft 365. CodeTwo said in June 2024 that Google Workspace support was in development, but its own site didn't show a launch when we checked in November 2026. Confirm with CodeTwo if you need it.

Is there a CodeTwo alternative that doesn't relay mail?

Yes. Outlook add-ins, such as Letsignit's, insert the signature while the user writes. Atlas Ink writes the signature into each mailbox from your own Azure subscription and never routes mail through Atlas; its optional stamping for other clients is a rule in your own Exchange Online, not a vendor relay.

Is there a free alternative to CodeTwo?

Exchange Online mail flow rules can add a signature or disclaimer to every message at no extra cost. Senders can't see it while writing or in Sent Items, and it can't sit directly under the latest reply, so it suits a legal footer better than a designed signature.

Was CodeTwo acquired?

No. CodeTwo describes itself as an independent software vendor, founded in 2007 and still owned by its founders, with offices in Poland.

Last updated 9 November 2026. Competitor details are drawn from each vendor's public pages, checked on 9 November 2026: CodeTwo's Email Signatures 365, Email Signatures On-prem, Exchange Rules, Google Workspace update and about pages; Exclaimer's email signature software and data residency pages; Crossware; Opensense; Letsignit's Outlook integration; WiseStamp; Rocketseed; and Microsoft's signatures and disclaimers and mail flow rule disclaimers pages. They're summarized in good faith; confirm current features and terms with each vendor. CodeTwo is a trademark of its owner; this article is not affiliated with or endorsed by CodeTwo.