diff --git a/backend/jmap/build.gradle b/backend/jmap/build.gradle
index cfd8995f6..c74ebd552 100644
--- a/backend/jmap/build.gradle
+++ b/backend/jmap/build.gradle
@@ -12,7 +12,7 @@ dependencies {
     api project(":backend:api")
 
     api "com.squareup.okhttp3:okhttp:${versions.okhttp}"
-    implementation "rs.ltt.jmap:jmap-client:0.2.4"
+    implementation "rs.ltt.jmap:jmap-client:0.3.0"
     implementation "com.jakewharton.timber:timber:${versions.timber}"
 
     testImplementation project(":mail:testing")
diff --git a/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandRefreshFolderList.kt b/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandRefreshFolderList.kt
index 671c86c26..8aa743839 100644
--- a/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandRefreshFolderList.kt
+++ b/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandRefreshFolderList.kt
@@ -46,7 +46,9 @@ internal class CommandRefreshFolderList(
     }
 
     private fun fetchMailboxes() {
-        val call = jmapClient.call(GetMailboxMethodCall(accountId))
+        val call = jmapClient.call(
+            GetMailboxMethodCall.builder().accountId(accountId).build()
+        )
         val response = call.getMainResponseBlocking<GetMailboxMethodResponse>()
         val foldersOnServer = response.list
 
@@ -91,19 +93,24 @@ internal class CommandRefreshFolderList(
 
     private fun fetchMailboxChanges(state: String): UpdateState {
         val multiCall = jmapClient.newMultiCall()
-        val mailboxChangesCall = multiCall.call(ChangesMailboxMethodCall(accountId, state))
+        val mailboxChangesCall = multiCall.call(
+            ChangesMailboxMethodCall.builder()
+                .accountId(accountId)
+                .sinceState(state)
+                .build()
+        )
         val createdMailboxesCall = multiCall.call(
-            GetMailboxMethodCall(
-                accountId,
-                mailboxChangesCall.createResultReference(ResultReference.Path.CREATED)
-            )
+            GetMailboxMethodCall.builder()
+                .accountId(accountId)
+                .idsReference(mailboxChangesCall.createResultReference(ResultReference.Path.CREATED))
+                .build()
         )
         val changedMailboxesCall = multiCall.call(
-            GetMailboxMethodCall(
-                accountId,
-                mailboxChangesCall.createResultReference(ResultReference.Path.UPDATED),
-                mailboxChangesCall.createResultReference(ResultReference.Path.UPDATED_PROPERTIES)
-            )
+            GetMailboxMethodCall.builder()
+                .accountId(accountId)
+                .idsReference(mailboxChangesCall.createResultReference(ResultReference.Path.UPDATED))
+                .propertiesReference(mailboxChangesCall.createResultReference(ResultReference.Path.UPDATED_PROPERTIES))
+                .build()
         )
         multiCall.execute()
 
diff --git a/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandSync.kt b/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandSync.kt
index 3fef1ab22..eea8d2bdc 100644
--- a/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandSync.kt
+++ b/backend/jmap/src/main/java/com/fsck/k9/backend/jmap/CommandSync.kt
@@ -78,8 +78,13 @@ class CommandSync(
             Timber.d("Fetching all messages in %s (%s)", backendFolder.name, folderServerId)
         }
 
-        val queryEmailMethod = QueryEmailMethodCall(accountId, createEmailQuery(folderServerId), limit)
-        val queryEmailCall = jmapClient.call(queryEmailMethod)
+        val queryEmailCall = jmapClient.call(
+            QueryEmailMethodCall.builder()
+                .accountId(accountId)
+                .query(createEmailQuery(folderServerId))
+                .limit(limit)
+                .build()
+        )
         val queryEmailResponse = queryEmailCall.getMainResponseBlocking<QueryEmailMethodResponse>()
         val queryState = if (queryEmailResponse.isCanCalculateChanges) queryEmailResponse.queryState else null
         val remoteServerIds = queryEmailResponse.ids.toSet()
@@ -113,8 +118,13 @@ class CommandSync(
         Timber.d("Updating messages in %s (%s)", backendFolder.name, folderServerId)
 
         val emailQuery = createEmailQuery(folderServerId)
-        val queryChangesEmailMethod = QueryChangesEmailMethodCall(accountId, queryState, emailQuery)
-        val queryChangesEmailCall = jmapClient.call(queryChangesEmailMethod)
+        val queryChangesEmailCall = jmapClient.call(
+            QueryChangesEmailMethodCall.builder()
+                .accountId(accountId)
+                .sinceQueryState(queryState)
+                .query(emailQuery)
+                .build()
+        )
 
         val queryChangesEmailResponse = try {
             queryChangesEmailCall.getMainResponseBlocking<QueryChangesEmailMethodResponse>()
@@ -200,8 +210,13 @@ class CommandSync(
     }
 
     private fun getEmailPropertiesFromServer(emailIdsChunk: List<String>, properties: Array<String>): List<Email> {
-        val getEmailMethod = GetEmailMethodCall(accountId, emailIdsChunk.toTypedArray(), properties)
-        val getEmailCall = jmapClient.call(getEmailMethod)
+        val getEmailCall = jmapClient.call(
+            GetEmailMethodCall.builder()
+                .accountId(accountId)
+                .ids(emailIdsChunk.toTypedArray())
+                .properties(properties)
+                .build()
+        )
 
         val getEmailResponse = getEmailCall.getMainResponseBlocking<GetEmailMethodResponse>()
         return getEmailResponse.list.toList()