diff --git a/Mailbox-Properties-Client.md b/Mailbox-Properties-Client.md
index 89ed6d7..a152562 100644
--- a/Mailbox-Properties-Client.md
+++ b/Mailbox-Properties-Client.md
@@ -3,7 +3,7 @@ The mailbox properties client is a [BSP client](https://code.briarproject.org/br
 
 ### Identifier
 
-The client's identifier is `org.briarproject.bramble.mailbox`. The major version is 0.
+The client's identifier is `org.briarproject.bramble.mailbox`. The major version is 1.
 
 ### Groups
 
@@ -11,21 +11,21 @@ The client uses a separate BSP group for communicating with each contact. The [g
 
 ### Message types
 
-**UPDATE** - The message body is a BDF list with 4 elements: `version` (int), `properties` (dictionary), `clientSupports` (list), and `serverSupports` (list).
+**UPDATE** - The message body is a BDF list with 4 elements: `version` (int), `clientSupports` (list), and `serverSupports` (list), `properties` (dictionary).
 
-`version` is incremented whenever the properties change. The keys of the `properties` dictionary are strings.
+`version` is incremented whenever the properties change.
 
-For major version 0, the `properties` dictionary of a well-formed update contains either no (0) entries, which means for the receiver that there is no mailbox available. Or, it contains all of the following entries:
+`clientSupports` is a non-empty list of Mailbox API versions that the sender can talk to as a client. Each element (a version) is a list with 2 elements: `major` (int), `minor` (int).
+
+`serverSupports` is a list of Mailbox API versions that the sender's mailbox supports. The list must be empty if `properties` is empty (there is no mailbox), otherwise it must be non-empty. Each element (a version) is a list with 2 elements: `maj` (int), `min` (int).
+
+The keys of the `properties` dictionary are strings. The dictionary of a well-formed update contains either no (0) entries, which means for the receiver that there is no mailbox available. Or, it contains all of the following entries:
 
 * "onion" : String -- Onion of the mailbox (56 lower-case base32 chars, derived from the v3 Onion Service public key)
 * "authToken" : byte[32] -- token used for authenticating with the mailbox
 * "inboxId" : byte[32] -- folder id used when receiving data from the mailbox
 * "outboxId" : byte[32] -- folder id used when delivering data to the mailbox
 
-`clientSupports` is a non-empty list of Mailbox API versions that the sender can talk to as a client. Each element (a version) is a list with 2 elements: `maj` (int), `min` (int).
-
-`serverSupports` is a list of Mailbox API versions that the sender's mailbox supports. The list must be empty if `properties` is empty (there is no mailbox), otherwise it must be non-empty. Each element (a version) is a list with 2 elements: `maj` (int), `min` (int).
-
 ### Validity policy
 
 * An update is valid if it is well-formed.