diff --git a/internal/bridge/user_events.go b/internal/bridge/user_events.go
index 343b2d96..402a6f2b 100644
--- a/internal/bridge/user_events.go
+++ b/internal/bridge/user_events.go
@@ -51,6 +51,9 @@ func (bridge *Bridge) handleUserEvent(ctx context.Context, user *user.User, even
 
 	case events.UserDeauth:
 		bridge.handleUserDeauth(ctx, user)
+
+	case events.UserBadEvent:
+		bridge.handleUserBadEvent(ctx, user)
 	}
 
 	return nil
@@ -130,3 +133,9 @@ func (bridge *Bridge) handleUserDeauth(ctx context.Context, user *user.User) {
 		bridge.logoutUser(ctx, user, false, false)
 	}, bridge.usersLock)
 }
+
+func (bridge *Bridge) handleUserBadEvent(ctx context.Context, user *user.User) {
+	safe.Lock(func() {
+		bridge.logoutUser(ctx, user, true, false)
+	}, bridge.usersLock)
+}
diff --git a/internal/events/user.go b/internal/events/user.go
index e07faaf8..216069f6 100644
--- a/internal/events/user.go
+++ b/internal/events/user.go
@@ -23,6 +23,7 @@ import (
 	"github.com/ProtonMail/proton-bridge/v3/internal/vault"
 )
 
+// AllUsersLoaded is emitted when all users have been loaded.
 type AllUsersLoaded struct {
 	eventBase
 }
@@ -31,6 +32,7 @@ func (event AllUsersLoaded) String() string {
 	return "AllUsersLoaded"
 }
 
+// UserLoading is emitted when a user is being loaded.
 type UserLoading struct {
 	eventBase
 
@@ -41,6 +43,7 @@ func (event UserLoading) String() string {
 	return fmt.Sprintf("UserLoading: UserID: %s", event.UserID)
 }
 
+// UserLoadSuccess is emitted when a user has been loaded successfully.
 type UserLoadSuccess struct {
 	eventBase
 
@@ -51,6 +54,7 @@ func (event UserLoadSuccess) String() string {
 	return fmt.Sprintf("UserLoadSuccess: UserID: %s", event.UserID)
 }
 
+// UserLoadFail is emitted when a user has failed to load.
 type UserLoadFail struct {
 	eventBase
 
@@ -62,6 +66,7 @@ func (event UserLoadFail) String() string {
 	return fmt.Sprintf("UserLoadFail: UserID: %s, Error: %s", event.UserID, event.Error)
 }
 
+// UserLoggedIn is emitted when a user has logged in.
 type UserLoggedIn struct {
 	eventBase
 
@@ -72,6 +77,7 @@ func (event UserLoggedIn) String() string {
 	return fmt.Sprintf("UserLoggedIn: UserID: %s", event.UserID)
 }
 
+// UserLoggedOut is emitted when a user has logged out.
 type UserLoggedOut struct {
 	eventBase
 
@@ -82,6 +88,7 @@ func (event UserLoggedOut) String() string {
 	return fmt.Sprintf("UserLoggedOut: UserID: %s", event.UserID)
 }
 
+// UserDeauth is emitted when a user has lost its API authentication.
 type UserDeauth struct {
 	eventBase
 
@@ -92,6 +99,19 @@ func (event UserDeauth) String() string {
 	return fmt.Sprintf("UserDeauth: UserID: %s", event.UserID)
 }
 
+// UserBadEvent is emitted when a user cannot apply an event.
+type UserBadEvent struct {
+	eventBase
+
+	UserID string
+	Error  error
+}
+
+func (event UserBadEvent) String() string {
+	return fmt.Sprintf("UserBadEvent: UserID: %s, Error: %s", event.UserID, event.Error)
+}
+
+// UserDeleted is emitted when a user has been deleted.
 type UserDeleted struct {
 	eventBase
 
@@ -102,6 +122,7 @@ func (event UserDeleted) String() string {
 	return fmt.Sprintf("UserDeleted: UserID: %s", event.UserID)
 }
 
+// UserChanged is emitted when a user's data has changed (name, email, etc.).
 type UserChanged struct {
 	eventBase
 
@@ -112,6 +133,7 @@ func (event UserChanged) String() string {
 	return fmt.Sprintf("UserChanged: UserID: %s", event.UserID)
 }
 
+// UserRefreshed is emitted when an API refresh was issued for a user.
 type UserRefreshed struct {
 	eventBase
 
@@ -122,6 +144,7 @@ func (event UserRefreshed) String() string {
 	return fmt.Sprintf("UserRefreshed: UserID: %s", event.UserID)
 }
 
+// AddressModeChanged is emitted when a user's address mode has changed.
 type AddressModeChanged struct {
 	eventBase
 
diff --git a/internal/user/events.go b/internal/user/events.go
index 707a83b4..736e4cb6 100644
--- a/internal/user/events.go
+++ b/internal/user/events.go
@@ -670,9 +670,8 @@ func getMailboxName(label proton.Label) []string {
 
 func waitOnIMAPUpdates(ctx context.Context, updates []imap.Update) error {
 	for _, update := range updates {
-		err, ok := update.WaitContext(ctx)
-		if ok && err != nil {
-			return fmt.Errorf("failed to apply gluon update %v :%w", update.String(), err)
+		if err, ok := update.WaitContext(ctx); ok && err != nil {
+			return fmt.Errorf("failed to apply gluon update %v: %w", update.String(), err)
 		}
 	}
 
diff --git a/internal/user/user.go b/internal/user/user.go
index 3c89b904..18caf83d 100644
--- a/internal/user/user.go
+++ b/internal/user/user.go
@@ -20,6 +20,7 @@ package user
 import (
 	"context"
 	"crypto/subtle"
+	"errors"
 	"fmt"
 	"io"
 	"strings"
@@ -552,29 +553,54 @@ func (user *User) doEventPoll(ctx context.Context) error {
 		return fmt.Errorf("failed to get event: %w", err)
 	}
 
-	if event.EventID != user.vault.EventID() {
-		user.log.WithFields(logrus.Fields{
-			"old": user.vault.EventID(),
-			"new": event,
-		}).Info("Received new API event")
-
-		// Handle the event.
-		if err := user.handleAPIEvent(ctx, event); err != nil {
-			return fmt.Errorf("failed to handle event: %w", err)
-		}
-
-		user.log.WithField("event", event).Debug("Handled API event")
-
-		// Update the event ID in the vault.
-		if err := user.vault.SetEventID(event.EventID); err != nil {
-			return fmt.Errorf("failed to update event ID: %w", err)
-		}
-
-		user.log.WithField("eventID", event.EventID).Debug("Updated event ID in vault")
-	} else {
+	// If the event ID hasn't changed, there are no new events.
+	if event.EventID == user.vault.EventID() {
 		user.log.Debug("No new API events")
+		return nil
 	}
 
+	user.log.WithFields(logrus.Fields{
+		"old": user.vault.EventID(),
+		"new": event,
+	}).Info("Received new API event")
+
+	// Handle the event.
+	if err := user.handleAPIEvent(ctx, event); err != nil {
+		// If the error is a network error, return error to retry later.
+		if netErr := new(proton.NetError); errors.As(err, &netErr) {
+			return fmt.Errorf("failed to handle event due to network issue: %w", err)
+		}
+
+		// If the error is a server-side issue, return error to retry later.
+		if apiErr := new(proton.APIError); errors.As(err, &apiErr) && apiErr.Status >= 500 {
+			return fmt.Errorf("failed to handle event due to server error: %w", err)
+		}
+
+		// Otherwise, the error is a client-side issue; notify bridge to handle it.
+		user.log.WithField("event", event).Warn("Failed to handle API event")
+
+		user.eventCh.Enqueue(events.UserBadEvent{
+			UserID: user.ID(),
+			Error:  err,
+		})
+
+		return fmt.Errorf("failed to handle event due to client error: %w", err)
+	}
+
+	user.log.WithField("event", event).Debug("Handled API event")
+
+	// Update the event ID in the vault. If this fails, notify bridge to handle it.
+	if err := user.vault.SetEventID(event.EventID); err != nil {
+		user.eventCh.Enqueue(events.UserBadEvent{
+			UserID: user.ID(),
+			Error:  err,
+		})
+
+		return fmt.Errorf("failed to update event ID: %w", err)
+	}
+
+	user.log.WithField("eventID", event.EventID).Debug("Updated event ID in vault")
+
 	return nil
 }