Company Email Signatures on Mobile: iPhone, Android, the Gmail App and Apple Mail (2026 IT Guide)

TL;DR: Every mobile email app keeps its own signature setting, and most of them can't be managed from the outside. Outlook for iOS and Android accept an admin-deployed signature add-in. The Gmail iOS app can carry a centrally set signature if users leave "Mobile Signature" off. Gmail for Android and Apple Mail on iPhone can't be managed client-side, and Apple Mail on iPhone only takes plain text. The only way to put the full company signature on every message sent from every phone is server-side: route outbound mail through a signature service that adds the signature in transit. Most companies combine both: client-side where the app allows it, server-side as the fallback.

Last reviewed: October 2026.

A signature program that looks complete on desktop usually leaks on phones. Sales and field staff send a large share of their email from mobile, often from whichever app came with the phone, and those messages go out with "Sent from my iPhone" or an old title typed in years ago. This guide is for the IT and marketing teams who own the signature: how each mobile app handles signatures, what a signature tool can and can't control in each, how server-side routing closes the gap, what Intune and other device management can do, and how to design and test signatures for small screens. For single-user steps, see Scribe's posts on adding a signature in Apple Mail on iPhone and adding a signature in the Gmail app.

Why is mobile where signature consistency breaks?

• Each app stores its own signature. Gmail's apps, Outlook's apps and Apple Mail all have a per-device or per-account signature field that is separate from the one IT manages on desktop or web.
• Apps default to their own branding. Outlook mobile appends "Get Outlook for iOS" or "Get Outlook for Android" when no signature is defined (Microsoft Learn), and Apple Mail's default is "Sent from my iPhone".
• Some apps don't allow injection. Scribe's documentation is explicit that Gmail for Android and Apple Mail "don't allow external tools to modify the signature in the compose window, which is a technical limitation of those apps" (Scribe: do signatures work on mobile?).
• Personal phones are unmanaged. On BYOD devices, IT often can't push app settings at all.

Note that the problem is only about sending from a phone. A signature added on desktop or web is part of the message, so it displays on the recipient's phone whatever app they use (same Scribe page).

How does each mobile app handle signatures natively?

App	Where the signature lives	Formatting	Notes for IT
Gmail for iPhone and iPad	Settings > Signature settings, per account; "Mobile Signature" toggle	Set in the app	Google: "If you don't create a signature in the Gmail app, new messages use the signature that you set up on your computer."
Gmail for Android	Per-account mobile signature in the app	Set in the app	Google documents the same fallback to the computer signature; Scribe still lists Android as not covered client-side (see below)
Outlook for iOS and Android	Signature setting in the app	Set in the app	Default "Get Outlook" line; Intune can disable it; supports event-based add-ins
Apple Mail on iPhone	Settings > Apps > Mail > Signature, all accounts or per account	"You can only use text in your Mail signatures"	No HTML, logo or banner can be set on the device
Apple Mail on Mac	Mail > Settings > Signatures	Rich text and images	A desktop app can manage it; see the Apple Mail section

Sources: Google's Gmail signature help for iPhone and iPad and Android; Apple's Mail settings on iPhone and Mail on Mac; Microsoft's Intune configuration page above.

What can a signature tool manage on each app?

This is Scribe's documented coverage. Other vendors face the same app-level limits, so the pattern is similar even if the details differ.

Sending app	Client-side (no mail rerouting)	Server-side (routed through Scribe)
Outlook for iOS	Yes, via the Microsoft 365 add-in	Yes
Outlook for Android	Yes, via the Microsoft 365 add-in	Yes
Gmail for iOS	Yes, via the Google Workspace app	Yes
Gmail for Android	No	Yes
Apple Mail on iPhone	No	Yes
Apple Mail on Mac	Per-device desktop app (manual or RMM)	Yes

Sources: Scribe mobile matrix, Microsoft 365 add-in (Web, Desktop, iOS, Android), Google Workspace app (Web, iOS), and the server-side guides for Microsoft 365 and Google Workspace (Web, Desktop, Apple Mail, iOS, Android).

A note on Gmail for Android. Google's help says the Android app falls back to the computer signature when no mobile signature exists, which suggests a signature written into Gmail settings could appear there. Scribe nevertheless supports Gmail for Android only with server-side installation, available on the Business and Enterprise plans, so plan server-side for Android-heavy teams. Scribe's pricing page lists "Gmail Web, Desktop, IOS, Android" under compatibility; that row describes what's possible across both installation methods, and the help center is the authority for which method covers which app.

What works client-side without rerouting mail?

Outlook for iOS and Android

Microsoft supports the OnNewMessageCompose event, which signature add-ins use, in Outlook for iOS and Android from version 4.2352.0, provided the add-in is admin-deployed and uses the add-in only manifest (Microsoft Learn: event-based activation in Outlook mobile). Behaviors to expect:

• A locally saved signature flashes briefly, then the add-in replaces it.
• Messages started from the iOS Share sheet don't trigger the event, so they go out without the add-in's signature.
• Replying from the bottom of a message adds the signature, but it only becomes visible when the compose window is expanded.
• Only one event-based add-in runs at a time, for at most 60 seconds.

For Scribe tenants, some add-in updates must be approved once in Microsoft 365 admin center > Settings > Integrated apps; Scribe lists automatic installation in the iOS and Android Outlook apps as a reason to approve (Scribe: update the Microsoft add-in). The Outlook guide covers the full client matrix.

Gmail for iPhone and iPad

With Scribe's Google Workspace app, the signature is written into each user's Gmail settings, and the Gmail iOS app uses it as long as the app's own Mobile Signature option is off. Two things surprise users: the signature "gets installed after you send an email", so it isn't visible while composing, and a mobile signature someone set up earlier overrides it (Scribe: Gmail iOS app signature not showing up). Add "turn off Mobile Signature" to your rollout instructions.

Apple Mail

On a Mac, Scribe's desktop app installs the signature into Apple Mail; each user installs it, or IT pushes the DMG through an RMM tool (Scribe: Apple Mail, Apple Mail RMM). There's no documented equivalent for Apple Mail on iPhone, and the app accepts only text signatures, so server-side is the route there.

How does server-side give full mobile coverage?

Server-side installation "changes your mail routing, not your teammates' mailboxes": a rule in Exchange Online or Google Workspace sends outbound mail to the signature service over TLS, the service inserts the right signature and re-signs the message, and it returns to your platform for delivery (Scribe: Google Workspace server side). Because the signature is added after the message leaves the device, the app the person used doesn't matter. Things to plan for:

• Users don't see the signature while writing, and the Sent folder copy doesn't include it. Recipients always get it.
• DKIM changes. Inserting a signature invalidates the original DKIM signature, so the service re-signs. Scribe publishes a key at scribe._domainkey and adds an ARC chain; SPF is unaffected because your platform still delivers the message. Validate DNS before enabling the rule.
• Combine it with client-side. When both are connected, Scribe defaults to client-side so users see their signature where the app allows it, and server-side covers the rest (Scribe mobile). The server checks whether the body already carries the signature before inserting one, so messages don't get two.
• Reply and internal variants still work: Scribe picks the on-reply variant when the subject starts with a reply or forward prefix, and the internal variant when every recipient is on the sender's domain.

Setup steps and the security questions your review will ask are in the Microsoft 365 and Google Workspace guides and the client-side vs server-side comparison.

What can Intune, Jamf and other device management do?

• Intune and Outlook mobile. An app configuration policy targeting Outlook can switch off the default "Get Outlook" signature with Default app signature (com.microsoft.outlook.Mail.DefaultSignatureEnabled = false). Microsoft lists the key for both managed devices and managed apps, so it can reach BYOD phones where only the Outlook app is managed (Microsoft Learn). It doesn't set a company signature. CodeTwo has reported that this policy once blocked all signatures in Outlook for Android (CodeTwo KB); test before rolling out.
• Intune and images. The same policy has a Block external images setting whose default (value 1) blocks images hosted on the internet unless the sender is internal or a Safe Sender. Internal recipients still see hosted logos; external recipients' own settings decide what they see.
• Apple devices (Jamf, Intune, other MDM). We haven't found an Apple-documented MDM setting that pushes a formatted signature to Mail on iPhone, and Apple says Mail signatures on iPhone are text only. Device management can install the Scribe desktop app on Macs; for iPhones, use server-side routing or steer users to Outlook or Gmail.
• Personal phones. If you can't manage the device, you can still manage the mail flow. Server-side applies to company accounts on any phone.

How do you make signatures render well on phones?

• Keep it narrow and short. Most phone screens show roughly 320 to 430 CSS pixels of width. A signature built on a single column, or columns that stack, reads better than a wide two-column card. Scribe states its signatures are responsive by default and generated as inline-styled, table-based HTML (Scribe: compatibility).
• Size images for the display, upload them at twice that. Set an explicit width and height in pixels, and use a source image about twice as large so it stays sharp on high-density screens. The image size guide has dimensions per element.
• Keep file sizes small. Scribe accepts images up to 5 MB, but recommends keeping GIFs under 2 MB "to avoid slow loading times on mobile devices" and using one animated element per signature (Scribe: GIFs).
• Make phone numbers and links tappable. Use tel: links for numbers and leave space between icons so a thumb hits the right one.
• Plan for dark mode. Mobile apps often invert colors. Scribe doesn't offer dark-mode image variants because no reliable cross-client method exists; it advises logos that stay visible on light and dark backgrounds, for example with a solid background (Scribe: image library). Its preview has a dark mode toggle for checking (Scribe: preview).
• Use web-safe fonts. Phone mail apps fall back to system fonts when they meet a custom font. Scribe limits signatures to 11 web-safe fonts, such as Helvetica, Arial and Georgia, for that reason (Scribe: fonts).
• Use a lighter reply variant. Most mobile mail is replies. A short on-reply variant without the banner keeps threads readable on a small screen. Scribe applies variants in Outlook and with server-side installation on paid plans, not with the standard Gmail integration (Scribe: variants).

How do you test a mobile rollout?

Use one pilot account per platform and send to an external mailbox you can open on both a phone and a computer. For each row, test a new message, a reply and a forward.

Send from	Expected with client-side only	Expected with client-side + server-side
Outlook for iOS / Android	Signature from the add-in (check app version and add-in update status)	Add-in signature; server doesn't add a second one
Gmail for iOS	Signature appears after sending, with Mobile Signature off	Same
Gmail for Android	Not covered	Signature added in transit
Apple Mail on iPhone	Not covered; the device's own text signature, if any, is sent	Signature added in transit (ask users to clear "Sent from my iPhone")
Share sheet on iOS (Outlook)	No add-in signature	Signature added in transit

Check also that the Sent folder copy looks as expected (server-side additions don't appear there), that the logo loads for an external recipient, and that the reply variant is used on replies.

Where does Scribe fit for mobile?

Scribe covers mobile with two methods from one dashboard. Client-side, the Microsoft 365 add-in reaches Outlook for iOS and Android and the Google Workspace app reaches the Gmail iOS app, with no change to mail flow. Server-side routing for Microsoft 365 or Google Workspace, on the Business and Enterprise plans, covers Gmail for Android, Apple Mail and every other app, and Scribe falls back to it automatically where client-side can't reach. Per-teammate installation statuses show who is covered (Scribe: statuses), and the same data is available through the API and the MCP server if you want to audit coverage from a script or an AI assistant. Pricing is per user, with a free plan for up to two users and a 14-day trial (pricing).

Frequently asked questions

Can IT set the email signature on employees' phones centrally?

Partly. An admin-deployed add-in can insert the signature in Outlook for iOS and Android, and a signature written into Gmail settings is used by the Gmail iPhone app when Mobile Signature is off. Gmail for Android and Apple Mail on iPhone can't be managed this way, so full coverage needs server-side routing, which adds the signature in transit.

How does the Gmail mobile signature work?

The Gmail app has its own mobile signature per account. Google says that if you don't create one in the app, new messages use the signature set on the computer. With a centrally managed Gmail signature, users should leave the app's Mobile Signature option off so it doesn't override the company version.

Why doesn't my company signature show in Apple Mail on iPhone?

Apple Mail on iPhone keeps its own signature, and Apple says you can only use text in it, so no tool can install a formatted signature in the app. Signatures can be added to mail sent from Apple Mail on iPhone only server-side, after the message is sent.

Do email signatures work on Android?

In Outlook for Android, yes, through an admin-deployed add-in on Outlook 4.2352.0 or later. In Gmail for Android, Scribe supports signatures only with server-side installation, on the Business and Enterprise plans.

How do I remove "Get Outlook for iOS" from company emails?

Create an Intune app configuration policy for Outlook and set Default app signature to Off, which is the key com.microsoft.outlook.Mail.DefaultSignatureEnabled set to false. Test on Android first: CodeTwo has reported that the setting once blocked all signatures in Outlook for Android.

Will server-side signatures appear in the sender's Sent folder on their phone?

No. The signature is added after the message leaves the mailbox, so the Sent copy is the pre-processing version. Recipients always receive the signature.

What size should a mobile email signature be?

Design for a narrow screen: a single column or stacking columns, images with explicit pixel dimensions uploaded at about twice their display size, small files (Scribe recommends GIFs under 2 MB), tappable tel: links and a short reply variant for threads.

Can Intune or Jamf push an email signature to iPhones?

Intune can turn off Outlook mobile's default signature but doesn't set a company signature, and we haven't found an Apple-documented MDM setting that pushes a formatted signature to Mail on iPhone. Use server-side routing for iPhones, or move users to Outlook or Gmail apps that can be managed client-side.

Related Handbook guides

• Client-side vs server-side email signatures
• Signatures in the new Outlook, Outlook on the web and Outlook mobile
• Google Workspace company-wide signatures
• Email signature size, images and hosting
• Email disclaimers by country and industry