Outlook signature not showing in replies and forwards? Fixes

Short answer: most often your signature is missing in replies/forwards because Outlook has a separate Replies/forwards setting that wasn’t set, or because the reply is being composed in Plain Text or RTF which strips HTML signatures. If client settings and message format look correct, server-side transport rules, gateway sanitizers, or shared-mailbox/delegate identity issues are likely and require an admin to check.

Symptom — what you see

Direct answer: your reply or forward opens without the signature you expect, while new messages still include it.

You compose a reply or forward and the signature isn’t at the bottom. New messages include the signature. This can happen only for certain recipients (external vs internal), when replying to messages from particular senders, or when sending from a specific From address such as a shared mailbox or a delegated identity.

Before you start (applicability and safe checks)

Direct answer: check scope, permissions and restart the client after changes; don’t edit server rules yourself.

• Scope: applies to Outlook desktop (classic and New Outlook), Outlook for Mac, Outlook on the web (Outlook.com / OWA), and Outlook mobile.

• Permissions: you must have access to the affected mailbox or the sending account. For shared mailboxes or "Send As" identities, test while sending from that identity.

• Restarts: after changing signature settings, restart the client so the change applies.

• What to avoid: don’t edit Exchange transport rules or gateway appliances unless you are the mailbox administrator. Collect evidence before asking IT.

• What to collect first: save a test message from Sent Items and the received copy with full headers. Also take screenshots of the signature settings and note the exact From address used.

Three-minute triage checklist

Direct answer: do three quick checks to rule out common causes.

1. Confirm the client’s Replies/forwards signature setting for the account you use to send.

2. Check the message format in the compose window and switch to HTML if it shows Plain Text or RTF.

3. Send a test from the same account to yourself, then reply from the same client and From address. Observe whether the signature appears.

If the signature appears when replying to your own test message, suspect an outbound gateway or recipient-side sanitizer. If it never appears, keep checking client settings and sending identity. If it appears intermittently, gather headers, Sent Items copies and timestamps for an admin.

Client checks and exact steps to set reply/forward signatures

Direct answer: pick the account, set the signature for both New messages and Replies/forwards, then restart and retest.

Before making changes: note the account and From address you will use in tests.

Classic Outlook (Windows) — stepwise:

1. Open File > Options > Mail.
2. Click Signatures... under "Compose messages".
3. Use the E-mail account dropdown to pick the account.
4. Set the signature for both New messages and Replies/forwards.

File > Options > Mail > Signatures...

Expected result: replies composed from that account include the chosen signature. If not, confirm you picked the correct account and restart Outlook.

New Outlook (Windows) — stepwise:

1. Click Settings (gear) and choose "View all Outlook settings" or open the Signatures entry.
2. In Signatures, pick the account and assign a signature for New messages and for Replies/forwards.

Note: New Outlook stores signatures separately from classic Outlook; if you switch apps, set signatures in both.

Outlook for Mac — stepwise:

1. Open Outlook > Preferences > Signatures.
2. Create or select a signature.
3. In "Default Signatures", assign it to the account for New messages and for Replies/forwards.

Outlook on the web (OWA) — stepwise:

1. Settings (gear) > "View all Outlook settings" > Mail > Compose and reply.
2. Set the default signature for New messages and for Replies/forwards for the account.

Outlook mobile (iOS/Android) — stepwise:

1. Open the Outlook app, go to Settings (profile or gear) > Signatures.
2. Confirm the account-specific signature.

If you use multiple profiles, shared mailboxes or delegate access: confirm the message’s From address is the identity you configured; the signature used is the one assigned to that sending identity. If you reply using a different From address, switch it to the intended identity and retest.

How message format (HTML / Plain Text / RTF) affects signatures and how to fix it

Direct answer: HTML signatures require an HTML compose window. Plain Text or RTF removes or breaks HTML signatures.

Why format matters: HTML signatures include markup and images that Plain Text removes. RTF can alter HTML and break inline images or styling.

Check and change the message format:

1. In the reply compose window, check whether the formatting toolbar shows formatting options or a Plain Text indicator.
2. If Plain Text or RTF is active, switch the message to HTML.

In reply window: Format Text > HTML

Expected result: the client can insert the HTML signature. If images still don’t appear, they may be remote and blocked by the recipient’s client or by gateway settings.

If you must send plain-text replies:

• Create a plain-text signature and set it as the reply signature.
• Keep plain-text signatures short: name, role, phone.

Repair a broken HTML signature:

• Open the signature editor and paste a cleaned, simple HTML fragment or recreate the signature there.
• Use inline styles and avoid external CSS or scripts.
• Prefer embedded images if allowed; otherwise omit logos from plain-text fallbacks.

If replies to external senders become plain text automatically, gateways or recipient-side settings often force that; collect evidence before escalating.

Shared mailboxes, delegates, server-side signatures and how to collect evidence

Direct answer: if client fixes fail, collect the Sent Items copy, the received copy with headers, screenshots, From address and timestamps before asking IT.

Shared mailbox and delegate checks — stepwise:

1. Verify the message is sent from the shared mailbox or delegate identity by checking Sent Items and the From line before sending.
2. Sign in directly to the shared mailbox (if allowed) or use OWA with the shared mailbox active and set its reply signature there.

Server-side causes to expect:

• Exchange Online / Microsoft 365 transport rules can append, replace or remove signatures.
• Third-party signature-management services or outbound gateways can add, strip or sanitize signatures after send.
• Admin policy can disable client-side signature insertion.

What to collect before you ask IT (one set per failing scenario):

• The sent message from Sent Items saved as a file (.msg from Outlook or .eml).
• The received copy saved as .eml if possible.
• Full message headers from both the sent copy and the received copy.
• Screenshots of the signature settings from the client where you composed the reply.
• The exact From address used and timestamps.

How to get headers and saves (minimal instructions):

1. Save the message from Sent Items as .msg (Outlook) or .eml.
2. On the received message, view message details or headers and save a copy. In Outlook desktop: open message > File > Properties to view internet headers.

If you suspect a transport rule or gateway, include message-IDs, timestamps and both header copies in your ticket.

Add-ins and security gateways: how to test and collect evidence

Direct answer: add-ins or outbound security products can rewrite or strip signatures. Test reproducibility and collect evidence before disabling anything.

Steps to isolate add-ins in Outlook desktop:

1. Reproduce the problem with add-ins enabled and save the failing Sent Items copy and headers.
2. Disable nonessential COM add-ins: File > Options > Add-ins, Manage COM Add-ins > Go, uncheck add-ins to disable, restart Outlook and retest.

If disabling add-ins is not allowed by policy, document the add-in list and versions and include that with your evidence for IT.

What to collect if you suspect a gateway:

• Sent message copy and received copy with full headers.
• The send and receive times and message-IDs.

If an add-in or gateway is confirmed, work with your admin or the gateway vendor; the evidence above reduces back-and-forth.

Short test plan to confirm a fix without repeatedly emailing external recipients

Direct answer: use a controlled test recipient you control and save both sent and received copies with headers to prove the fix.

1. Create a test recipient you control (external if the issue is external).
2. From the affected account, send a test message to that recipient. Save the Sent Items copy as .msg or .eml.
3. From the recipient mailbox, save the received message as .eml and capture full headers.
4. Reply to that received message from the recipient and confirm the reply contains the signature if expected; save that copy.
5. Repeat the test switching From to any alternate identities you use (shared mailbox, Send As, delegate).

What to collect for escalation: Sent Items file, received .eml, headers, screenshots of signature settings, exact From address used, and timestamps. Provide these to your mail admin and say whether the missing signature is only on replies, only on external recipients, or only when using a shared mailbox.

Verify: how to confirm the fix worked

Direct answer: restart, run the controlled test from the fixed account and From address, then check the received copy for the signature.

1. After changing settings or format, restart the client.
2. Send the controlled test from the account and From address you fixed to the test recipient.
3. Open the received copy and confirm the signature appears where expected.

Expected output: the received message shows the signature. If it does not, attach the Sent Items and received copies with headers and escalate to mail admin with the collected evidence.

Conclusion

If adjusting the Replies/forwards signature and message format fixes the issue, you’re done. If signatures still disappear, gather the Sent Items and received copies (with headers), screenshots of settings and the exact From address and timestamps, then escalate to your mail admin so they can check transport rules, gateway logs or shared-mailbox settings.