diff --git a/Apps/MagnumOpus/ViewModels/MailViewModel.swift b/Apps/MagnumOpus/ViewModels/MailViewModel.swift
index 7941d2c..a89b734 100644
--- a/Apps/MagnumOpus/ViewModels/MailViewModel.swift
+++ b/Apps/MagnumOpus/ViewModels/MailViewModel.swift
@@ -207,8 +207,10 @@ final class MailViewModel {
 			try await coordinator.syncNow()
 			syncState = coordinator.syncState
 		} catch {
-			errorMessage = error.localizedDescription
-			syncState = .error(error.localizedDescription)
+			let desc = "\(type(of: error)): \(error.localizedDescription)"
+			print("[MailViewModel] syncNow failed: \(desc)")
+			errorMessage = desc
+			syncState = .error(desc)
 		}
 	}
 
diff --git a/Packages/MagnumOpusCore/Sources/IMAPClient/IMAPResponseHandler.swift b/Packages/MagnumOpusCore/Sources/IMAPClient/IMAPResponseHandler.swift
index 1602d39..33429c7 100644
--- a/Packages/MagnumOpusCore/Sources/IMAPClient/IMAPResponseHandler.swift
+++ b/Packages/MagnumOpusCore/Sources/IMAPClient/IMAPResponseHandler.swift
@@ -53,6 +53,15 @@ final class IMAPResponseHandler: ChannelInboundHandler, RemovableChannelHandler,
 		}
 	}
 
+	func channelInactive(context: ChannelHandlerContext) {
+		let error = IMAPError.notConnected
+		continuation?.resume(throwing: error)
+		continuation = nil
+		greetingContinuation?.resume(throwing: error)
+		greetingContinuation = nil
+		context.fireChannelInactive()
+	}
+
 	func errorCaught(context: ChannelHandlerContext, error: Error) {
 		continuation?.resume(throwing: error)
 		continuation = nil
@@ -68,6 +77,11 @@ final class IMAPResponseHandler: ChannelInboundHandler, RemovableChannelHandler,
 	}
 
 	func sendCommand(tag: String, continuation cont: CheckedContinuation<[Response], Error>) {
+		// Resume any leaked continuation from a previous command to avoid
+		// "SWIFT TASK CONTINUATION MISUSE: leaked its continuation"
+		if let old = continuation {
+			old.resume(throwing: IMAPError.serverError("Previous command interrupted"))
+		}
 		expectedTag = tag
 		continuation = cont
 		buffer = []
diff --git a/Packages/MagnumOpusCore/Sources/MailStore/MailStore.swift b/Packages/MagnumOpusCore/Sources/MailStore/MailStore.swift
index d78744e..4affd2a 100644
--- a/Packages/MagnumOpusCore/Sources/MailStore/MailStore.swift
+++ b/Packages/MagnumOpusCore/Sources/MailStore/MailStore.swift
@@ -58,7 +58,8 @@ public final class MailStore: Sendable {
 	public func insertMessages(_ messages: [MessageRecord]) throws {
 		try dbWriter.write { db in
 			for message in messages {
-				try message.save(db)
+				// INSERT OR IGNORE: skip if (mailboxId, uid) already exists from a prior sync
+				try message.insert(db, onConflict: .ignore)
 			}
 		}
 	}