Front Not Syncing Emails (Gmail/O365): Causes & Fixes

Start here: symptom to likely cause

Before you change anything, match what you're seeing to the most probable culprit. Working top to bottom saves you from reauthorizing a channel when the real problem is a broken threading setting.

1. The channel connection has dropped — reauthorize it

This is the single most common cause, and the first thing to try when one channel stops syncing while your others keep working. Front connects to Gmail and Office 365 over OAuth, and that authorization can lapse — a password change, a revoked app grant, an admin security policy, or an expired token all quietly sever the link. Front keeps showing the channel, but nothing new flows through it.

The fix is to reauthorize. Go to Settings → Channels, open the affected inbox (for example your Gmail channel), and select its Settings tab. That tab is where the Reauthorize button lives — click it and complete the Google or Microsoft sign-in prompt to re-establish the connection.

As the caption notes, a healthy channel shows no scary "sync failed" banner — the Reauthorize button is simply always there as the recovery lever. Reauthorizing with the correct account is safe and is the same first step Front's own support recommends. One caution: reauthorize with the exact same mailbox the channel was originally connected to. Connecting a different Google or Microsoft account creates a new channel rather than repairing the old one. If you're not sure how the channel was wired up in the first place, how to connect Gmail to Front covers the original setup, and Front channels explained covers the different channel types.

2. Everything stopped at once — check for an outage

If every channel went silent simultaneously and you changed nothing, you're probably looking at an outage rather than a per-channel problem. This exact scenario shows up in Front's own community: one team reported inbound email landing in Gmail but "not showing up in any way in Front" across all channels, direct and shared, having made no configuration changes (community.front.com). They'd already tried restarting, updating, and reauthenticating before Front's support stepped in to investigate by message ID.

The fix here is triage, not tinkering:

1. Check status.frontapp.com for a reported Front incident.
2. Check the Google Workspace or Microsoft 365 status dashboard for a provider-side outage.
3. If both are green, reauthorize one channel (cause 1) to rule out a token issue.
4. If it's still dead across the board, that's the case to open a ticket — see is Front app down for how to confirm an outage versus a local problem before you escalate.

3. Someone performed one of the 5 sync-breaking actions

If sync mostly works but specific threads are missing, duplicated, or arriving on the wrong conversation, the cause is usually an action that Front explicitly warns breaks the Gmail/Office 365 link. Per Front's documentation on actions that break the sync, these five are the culprits:

1. Moving a conversation to an inbox it wasn't originally received in.
2. Replying from a different account than the one the message originated on.
3. Changing the threading mode so messages thread by Front's logic instead of native Gmail/Office 365 logic.
4. Splitting a conversation into separate threads.
5. Merging conversations — whether automatically via smart merge or manually.

The fix depends on which one bit you. If a teammate changed the threading mode, switch it back to native (Gmail/Office 365) threading under the channel's settings — Front-logic threading is the setting most likely to silently desync a shared inbox. For splits and merges, avoid repeating the action on affected threads. And critically: because these actions can put a conversation into a state Front can't cleanly reconcile, the affected messages may need Front's team to repair. Grab the message ID or email headers of a message that didn't sync and open a support ticket — that's the exact information Front asked for in the community thread above, and it's the fastest path to a fix for this class of problem.

4. You have the same account open in both Front and Gmail

This one is subtle and surprisingly common on teams that are still half-migrated to Front. Front is explicit: "You should not have the same account open in Gmail/Office 365 and in Front." The reasoning is that "navigating through Gmail/Office 365 may trigger actions you do not intend to within Front" (help.front.com) — archiving in Gmail, moving a message, or replying natively can all collide with Front's sync and produce missing or duplicated conversations.

The fix is a workflow rule, not a settings toggle: once a mailbox is connected to Front, handle it only in Front. Ask everyone who shares that inbox to close the native Gmail/Office 365 tab for that account. Front's own recommendation is to "only utilize Front to handle the email channels you've connected." If your team collaborates in a shared inbox, the whole point is a single surface — Front shared inbox explained covers why keeping work inside Front (comments, assignments, tags) rather than the underlying mailbox matters for exactly this reason.

5. Sync is working — you're just seeing normal latency or import scope

Not every "missing" email is a fault. Two behaviors look like sync failures but are entirely expected:

Initial import is still running. When you first connect a Gmail channel, Front imports history — and per Front's Gmail history import and sync documentation, that import can "take up to 72 hours to finish," pulling the "50K most recent messages" from newest to oldest. During that window, older conversations trickle in. That's not broken sync; it's the backfill catching up.

The 50K / reconnection limits. Front imports the 50,000 most recent messages, so genuinely old mail beyond that ceiling may never appear — that's by design, not a bug. And there's a second honest caveat worth knowing: for messages imported when a channel is reconnected, Front notes that "tags and statuses for these imported messages will not sync." More broadly, Front's two-way sync covers new messages, sent emails, and spam status — but read/unread status, archive/unarchive, tag changes, trash, and snooze actions are not synced between Gmail and Front. So if the "problem" is that a message you archived in Gmail is still open in Front, that's expected behavior, not a sync outage.

If new mail is simply arriving a few minutes late, give it time before escalating — brief latency is normal and self-resolves.

The honest limits — and where an AI layer helps

Most of the fixes above are quick, but two patterns need Front's support team rather than a self-serve toggle: a genuine cross-channel outage (cause 2) and threads mangled by a sync-breaking action (cause 3). In both, the message ID or email headers are what get you a resolution. Everything else — reauthorizing, closing the duplicate Gmail tab, reverting a threading change, waiting out an import — you can handle yourself.

There's also a quieter angle here. A meaningful share of the tickets sitting in a shared inbox are the routine, repetitive ones — and every one of those is a conversation a human has to open, read, and answer. Reducing that volume doesn't fix sync, but it does mean a temporary hiccup or a post-outage backlog is far less painful, because there's simply less human work queued behind it. That's the seam an AI agent layer fills. The broader category of AI agents for customer service exists for this, and Macha is one such layer: it runs on top of the Front you already use through the live Macha–Front connector — it doesn't replace Front, your channels, or your inboxes. When conversations flow in, Macha's agent reads them, understands intent, and drafts or sends grounded replies — pulling a real order or account status through a custom tool that turns your REST API into something the agent can call. Its credits are consumed per AI action, never per resolution. Your Front sync stays exactly as it is; the agent just handles the routine volume behind it.

FAQ

Why is my email in Gmail but not in Front? The most common cause is a dropped channel connection — reauthorize the affected channel under Settings → Channels → your channel → Settings. If every channel stopped at once, check status.frontapp.com and your provider's status page for an outage. If only specific threads are missing, one of Front's five sync-breaking actions (moving, replying from another account, changing threading, splitting, or merging) may have desynced them; contact Front with the message ID.

How do I reauthorize a channel in Front? Go to Settings → Channels, open the affected inbox, and click the Settings tab. The Reauthorize button lives there — click it and complete the Google or Microsoft sign-in. Always reauthorize with the same mailbox the channel was originally connected to, or you'll create a new channel instead of repairing the old one.

What actions break the sync between Front and Gmail/Office 365? Per Front's documentation, five actions can break sync: moving a conversation to an inbox it wasn't received in, replying from a different account than the message originated on, changing the threading mode to Front logic instead of native, splitting a conversation, and merging conversations (smart merge or manual).

Can I keep Gmail open while using Front? Front recommends against it. Having the same account open in both can trigger unintended actions in Front and cause missing or duplicated conversations. Once a mailbox is connected, handle it only in Front.

Why didn't my old emails import into Front? Front imports the 50,000 most recent messages, newest to oldest, and the import can take up to 72 hours. Mail older than that ceiling won't appear — that's by design. Read/unread, archive, tags, trash, and snooze also don't sync two-way between Gmail and Front.

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