diff --git a/SignalServiceKit/src/Contacts/Contact.m b/SignalServiceKit/src/Contacts/Contact.m
index c088eda73..0d362cc22 100644
--- a/SignalServiceKit/src/Contacts/Contact.m
+++ b/SignalServiceKit/src/Contacts/Contact.m
@@ -208,8 +208,8 @@ NS_ASSUME_NONNULL_BEGIN
     __block NSMutableArray *result = [NSMutableArray array];
 
     for (PhoneNumber *number in [self.parsedPhoneNumbers sortedArrayUsingSelector:@selector(compare:)]) {
-        SignalRecipient *signalRecipient =
-            [SignalRecipient recipientWithTextSecureIdentifier:number.toE164 withTransaction:transaction];
+        SignalRecipient *_Nullable signalRecipient =
+            [SignalRecipient registeredRecipientForRecipientId:number.toE164 transaction:transaction];
         if (signalRecipient) {
             [result addObject:signalRecipient];
         }
@@ -223,7 +223,7 @@ NS_ASSUME_NONNULL_BEGIN
 
     [OWSPrimaryStorage.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
         for (PhoneNumber *number in self.parsedPhoneNumbers) {
-            if ([SignalRecipient recipientWithTextSecureIdentifier:number.toE164 withTransaction:transaction]) {
+            if ([SignalRecipient isRegisteredSignalAccount:number.toE164 transaction:transaction]) {
                 [identifiers addObject:number.toE164];
             }
         }
diff --git a/SignalServiceKit/src/Contacts/SignalRecipient.h b/SignalServiceKit/src/Contacts/SignalRecipient.h
index 6f1d993d5..14611f818 100644
--- a/SignalServiceKit/src/Contacts/SignalRecipient.h
+++ b/SignalServiceKit/src/Contacts/SignalRecipient.h
@@ -9,9 +9,7 @@ NS_ASSUME_NONNULL_BEGIN
 // We hang the "known device list" for signal accounts on this entity.
 @interface SignalRecipient : TSYapDatabaseObject
 
-@property (readonly) NSOrderedSet *devices;
-
-@property (nonatomic) BOOL mayBeUnregistered;
+@property (nonatomic, readonly) NSOrderedSet *devices;
 
 - (instancetype)init NS_UNAVAILABLE;
 
@@ -28,9 +26,9 @@ NS_ASSUME_NONNULL_BEGIN
                                  transaction:(YapDatabaseReadWriteTransaction *)transaction;
 
 // TODO: Replace with cache of known signal account ids.
-+ (nullable instancetype)recipientWithTextSecureIdentifier:(NSString *)textSecureIdentifier;
-+ (nullable instancetype)recipientWithTextSecureIdentifier:(NSString *)textSecureIdentifier
-                                           withTransaction:(YapDatabaseReadTransaction *)transaction;
+// TODO: Remove?
++ (nullable instancetype)registeredRecipientForRecipientId:(NSString *)recipientId
+                                               transaction:(YapDatabaseReadTransaction *)transaction;
 
 - (void)addDevices:(NSSet *)set;
 - (void)removeDevices:(NSSet *)set;
@@ -39,6 +37,14 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (NSComparisonResult)compare:(SignalRecipient *)other;
 
+// TODO: Replace with cache of known signal account ids.
++ (BOOL)isRegisteredSignalAccount:(NSString *)recipientId transaction:(YapDatabaseReadTransaction *)transaction;
+
++ (void)markAccountAsRegistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction;
++ (void)markAccountAsNotRegistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction;
+
+- (void)markAccountAsNotRegisteredWithTransaction:(YapDatabaseReadWriteTransaction *)transaction;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Contacts/SignalRecipient.m b/SignalServiceKit/src/Contacts/SignalRecipient.m
index 062b19ab9..cb614f4e8 100644
--- a/SignalServiceKit/src/Contacts/SignalRecipient.m
+++ b/SignalServiceKit/src/Contacts/SignalRecipient.m
@@ -10,7 +10,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 @interface SignalRecipient ()
 
-@property NSOrderedSet *devices;
+@property (nonatomic) BOOL mayBeUnregistered;
+
+@property (nonatomic) NSOrderedSet *devices;
 
 @end
 
@@ -43,8 +45,7 @@ NS_ASSUME_NONNULL_BEGIN
 + (SignalRecipient *)ensureRecipientExistsWithRecipientId:(NSString *)recipientId
                                               transaction:(YapDatabaseReadWriteTransaction *)transaction
 {
-    SignalRecipient *_Nullable recipient =
-        [self recipientWithTextSecureIdentifier:recipientId withTransaction:transaction];
+    SignalRecipient *_Nullable recipient = [self recipientForRecipientId:recipientId transaction:transaction];
     if (recipient) {
         return recipient;
     }
@@ -60,8 +61,7 @@ NS_ASSUME_NONNULL_BEGIN
                                     deviceId:(UInt32)deviceId
                                  transaction:(YapDatabaseReadWriteTransaction *)transaction
 {
-    SignalRecipient *_Nullable existingRecipient =
-        [self recipientWithTextSecureIdentifier:recipientId withTransaction:transaction];
+    SignalRecipient *_Nullable existingRecipient = [self recipientForRecipientId:recipientId transaction:transaction];
     if (!existingRecipient) {
         DDLogDebug(@"%@ in %s creating recipient: %@, with deviceId: %u",
             self.logTag,
@@ -132,17 +132,37 @@ NS_ASSUME_NONNULL_BEGIN
     return self;
 }
 
-+ (nullable instancetype)recipientWithTextSecureIdentifier:(NSString *)textSecureIdentifier
-                                           withTransaction:(YapDatabaseReadTransaction *)transaction
+
++ (nullable instancetype)registeredRecipientForRecipientId:(NSString *)recipientId
+                                               transaction:(YapDatabaseReadTransaction *)transaction
+{
+    OWSAssert(transaction);
+    OWSAssert(recipientId.length > 0);
+
+    SignalRecipient *_Nullable instance = [self recipientForRecipientId:recipientId transaction:transaction];
+    if (instance && !instance.mayBeUnregistered) {
+        return instance;
+    } else {
+        return nil;
+    }
+}
+
++ (nullable instancetype)recipientForRecipientId:(NSString *)recipientId
+                                     transaction:(YapDatabaseReadTransaction *)transaction
 {
-    return [self fetchObjectWithUniqueID:textSecureIdentifier transaction:transaction];
+    OWSAssert(transaction);
+    OWSAssert(recipientId.length > 0);
+
+    return [self fetchObjectWithUniqueID:recipientId transaction:transaction];
 }
 
-+ (nullable instancetype)recipientWithTextSecureIdentifier:(NSString *)textSecureIdentifier
++ (nullable instancetype)recipientForRecipientId:(NSString *)recipientId
 {
+    OWSAssert(recipientId.length > 0);
+
     __block SignalRecipient *recipient;
-    [self.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *_Nonnull transaction) {
-        recipient = [self recipientWithTextSecureIdentifier:textSecureIdentifier withTransaction:transaction];
+    [self.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+        recipient = [self recipientForRecipientId:recipientId transaction:transaction];
     }];
     return recipient;
 }
@@ -150,7 +170,7 @@ NS_ASSUME_NONNULL_BEGIN
 // TODO This method should probably live on the TSAccountManager rather than grabbing a global singleton.
 + (instancetype)selfRecipient
 {
-    SignalRecipient *myself = [self recipientWithTextSecureIdentifier:[TSAccountManager localNumber]];
+    SignalRecipient *myself = [self recipientForRecipientId:[TSAccountManager localNumber]];
     if (!myself) {
         myself = [[self alloc] initWithTextSecureIdentifier:[TSAccountManager localNumber]];
     }
@@ -195,6 +215,67 @@ NS_ASSUME_NONNULL_BEGIN
     DDLogVerbose(@"%@ saved signal recipient: %@", self.logTag, self.recipientId);
 }
 
++ (BOOL)isRegisteredSignalAccount:(NSString *)recipientId
+{
+    __block BOOL result;
+    [self.dbReadConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
+        result = [self isRegisteredSignalAccount:recipientId transaction:transaction];
+    }];
+    return result;
+}
+
++ (BOOL)isRegisteredSignalAccount:(NSString *)recipientId transaction:(YapDatabaseReadTransaction *)transaction
+{
+    SignalRecipient *_Nullable instance = [self recipientForRecipientId:recipientId transaction:transaction];
+    return (instance && !instance.mayBeUnregistered);
+}
+
++ (void)markAccountAsRegistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSAssert(transaction);
+    OWSAssert(recipientId.length > 0);
+
+    SignalRecipient *_Nullable instance = [self recipientForRecipientId:recipientId transaction:transaction];
+
+    if (!instance) {
+        DDLogDebug(@"%@ creating recipient: %@", self.logTag, recipientId);
+
+        instance = [[self alloc] initWithTextSecureIdentifier:recipientId];
+        [instance saveWithTransaction:transaction];
+        return;
+    }
+    if (!instance.mayBeUnregistered) {
+        return;
+    }
+    instance.mayBeUnregistered = NO;
+    [instance saveWithTransaction:transaction];
+}
+
++ (void)markAccountAsNotRegistered:(NSString *)recipientId transaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSAssert(transaction);
+    OWSAssert(recipientId.length > 0);
+
+    SignalRecipient *_Nullable instance = [self recipientForRecipientId:recipientId transaction:transaction];
+    if (!instance) {
+        return;
+    }
+    if (instance.mayBeUnregistered) {
+        return;
+    }
+    instance.mayBeUnregistered = YES;
+    [instance saveWithTransaction:transaction];
+}
+
+- (void)markAccountAsNotRegisteredWithTransaction:(YapDatabaseReadWriteTransaction *)transaction
+{
+    OWSAssert(transaction);
+
+    self.mayBeUnregistered = YES;
+
+    [SignalRecipient markAccountAsNotRegistered:self.recipientId transaction:transaction];
+}
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Messages/OWSMessageSender.m b/SignalServiceKit/src/Messages/OWSMessageSender.m
index a0e80f1a6..a06b73cd2 100644
--- a/SignalServiceKit/src/Messages/OWSMessageSender.m
+++ b/SignalServiceKit/src/Messages/OWSMessageSender.m
@@ -712,11 +712,11 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
             [message updateWithSkippedRecipient:recipient.recipientId transaction:transaction];
         }
 
-        if (recipient.mayBeUnregistered) {
+        if (![SignalRecipient isRegisteredSignalAccount:recipient.recipientId transaction:transaction]) {
             return;
         }
-        recipient.mayBeUnregistered = YES;
-        [recipient saveWithTransaction:transaction];
+
+        [recipient markAccountAsNotRegisteredWithTransaction:transaction];
 
         [[TSInfoMessage userNotRegisteredMessageInThread:thread recipientId:recipient.recipientId]
             saveWithTransaction:transaction];
@@ -1016,10 +1016,9 @@ NSString *const OWSMessageSenderRateLimitedException = @"RateLimitedException";
             [recipient saveWithTransaction:transaction];
             [message updateWithSentRecipient:recipient.uniqueId transaction:transaction];
 
-            if (recipient.mayBeUnregistered) {
-                recipient.mayBeUnregistered = NO;
-                [recipient saveWithTransaction:transaction];
-            }
+            // If we've just delivered a message to a user, we know they
+            // have a valid Signal account.
+            [SignalRecipient markAccountAsRegistered:recipient.recipientId transaction:transaction];
         }];
 
         [self handleMessageSentLocally:message];