diff --git a/app/src/main/java/io/github/wulkanowy/data/mappers/MessageMapper.kt b/app/src/main/java/io/github/wulkanowy/data/mappers/MessageMapper.kt
index 120eb183..2ede5aa1 100644
--- a/app/src/main/java/io/github/wulkanowy/data/mappers/MessageMapper.kt
+++ b/app/src/main/java/io/github/wulkanowy/data/mappers/MessageMapper.kt
@@ -2,6 +2,7 @@ package io.github.wulkanowy.data.mappers
 
 import io.github.wulkanowy.data.db.entities.*
 import io.github.wulkanowy.sdk.pojo.MailboxType
+import timber.log.Timber
 import io.github.wulkanowy.sdk.pojo.Message as SdkMessage
 import io.github.wulkanowy.sdk.pojo.MessageAttachment as SdkMessageAttachment
 import io.github.wulkanowy.sdk.pojo.Recipient as SdkRecipient
@@ -16,7 +17,10 @@ fun List<SdkMessage>.mapToEntities(
         mailboxKey = mailbox?.globalKey ?: allMailboxes.find { box ->
             box.fullName == it.mailbox
         }?.globalKey.let { mailboxKey ->
-            requireNotNull(mailboxKey) { "Can't find ${it.mailbox} in $allMailboxes" }
+            if (mailboxKey == null) {
+                Timber.e("Can't find ${it.mailbox} in $allMailboxes")
+                "unknown"
+            } else mailboxKey
         },
         email = student.email,
         messageId = it.id,
diff --git a/app/src/main/java/io/github/wulkanowy/domain/messages/GetMailboxByStudentUseCase.kt b/app/src/main/java/io/github/wulkanowy/domain/messages/GetMailboxByStudentUseCase.kt
index a696d9b2..669514aa 100644
--- a/app/src/main/java/io/github/wulkanowy/domain/messages/GetMailboxByStudentUseCase.kt
+++ b/app/src/main/java/io/github/wulkanowy/domain/messages/GetMailboxByStudentUseCase.kt
@@ -17,8 +17,11 @@ class GetMailboxByStudentUseCase @Inject constructor(
     private fun List<Mailbox>.filterByStudent(student: Student): Mailbox? {
         val normalizedStudentName = student.studentName.normalizeStudentName()
 
-        return find {
+        return singleOrNull {
             it.studentName.normalizeStudentName() == normalizedStudentName
+        } ?: singleOrNull {
+            it.studentName.normalizeStudentName() == normalizedStudentName
+                && it.schoolNameShort == student.schoolShortName
         } ?: singleOrNull {
             it.studentName.getFirstAndLastPart() == normalizedStudentName.getFirstAndLastPart()
         } ?: singleOrNull {
diff --git a/app/src/test/java/io/github/wulkanowy/domain/GetMailboxByStudentUseCaseTest.kt b/app/src/test/java/io/github/wulkanowy/domain/GetMailboxByStudentUseCaseTest.kt
index 02980026..6db16d2f 100644
--- a/app/src/test/java/io/github/wulkanowy/domain/GetMailboxByStudentUseCaseTest.kt
+++ b/app/src/test/java/io/github/wulkanowy/domain/GetMailboxByStudentUseCaseTest.kt
@@ -160,8 +160,29 @@ class GetMailboxByStudentUseCaseTest {
         assertEquals(expectedMailbox, systemUnderTest(student))
     }
 
+    @Test
+    fun `get mailbox for student with mailboxes from two different schools`() = runTest {
+        val student = getStudentEntity(
+            userName = "Kamil Bednarek",
+            studentName = "Kamil Bednarek",
+            schoolShortName = "CKZiU",
+        )
+        val mailbox1 = getMailboxEntity(
+            studentName = "Kamil Bednarek",
+            schoolShortName = "ZSTiO",
+        )
+        val mailbox2 = getMailboxEntity(
+            studentName = "Kamil Bednarek",
+            schoolShortName = "CKZiU",
+        )
+        coEvery { mailboxDao.loadAll(any()) } returns listOf(mailbox1, mailbox2)
+
+        assertEquals(mailbox2, systemUnderTest(student))
+    }
+
     private fun getMailboxEntity(
         studentName: String,
+        schoolShortName: String = "test",
     ) = Mailbox(
         globalKey = "",
         fullName = "",
@@ -170,13 +191,14 @@ class GetMailboxByStudentUseCaseTest {
         schoolId = "",
         symbol = "",
         studentName = studentName,
-        schoolNameShort = "",
+        schoolNameShort = schoolShortName,
         type = MailboxType.STUDENT,
     )
 
     private fun getStudentEntity(
         studentName: String,
         userName: String,
+        schoolShortName: String = "test",
     ) = Student(
         scrapperBaseUrl = "http://fakelog.cf",
         email = "jan@fakelog.cf",
@@ -192,7 +214,7 @@ class GetMailboxByStudentUseCaseTest {
         privateKey = "",
         registrationDate = Instant.now(),
         schoolName = "",
-        schoolShortName = "test",
+        schoolShortName = schoolShortName,
         schoolSymbol = "",
         studentId = 1,
         studentName = studentName,