diff --git a/GUIs.Test.ZUGFeRDTest/Form1.vb b/GUIs.Test.ZUGFeRDTest/Form1.vb
index 3665395b..dab5e055 100644
--- a/GUIs.Test.ZUGFeRDTest/Form1.vb
+++ b/GUIs.Test.ZUGFeRDTest/Form1.vb
@@ -86,7 +86,10 @@ Public Class Form1
     End Function
 
     Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
-        Dim args As New WorkerArgs()
+        Dim args As New WorkerArgs() With {
+            .MaxAttachmentSizeInMegaBytes = 10,
+            .IgnoreRejectionStatus = False
+        }
         args = LoadFolderConfig(args)
         args = LoadPropertyMapFor(args, "DEFAULT")
         args.InsertIntoSQLServer = True
diff --git a/Modules.Jobs/EDMI/ZUGFeRD/EmailStrings.vb b/Modules.Jobs/EDMI/ZUGFeRD/EmailStrings.vb
index 2b94fb59..d68c3beb 100644
--- a/Modules.Jobs/EDMI/ZUGFeRD/EmailStrings.vb
+++ b/Modules.Jobs/EDMI/ZUGFeRD/EmailStrings.vb
@@ -23,6 +23,8 @@
 
     Public Const EMAIL_NO_FERDS = "<p>Ihre Email enthielt keine ZUGFeRD-Dokumente.</p>"
 
+    Public Const EMAIL_FILE_SIZE_REACHED = "<p>Ihre Email enthielt Dateien, die die erlaubte Größe von {0}MB überschreiten.</p>"
+
     Public Const EMAIL_INVALID_DOCUMENT = """
         <p>Ihre Email enthielt ein ZUGFeRD Dokument, welches aber inkorrekt formatiert wurde.</p>
         <p>Mögliche Gründe für ein inkorrektes Format:<ul>
diff --git a/Modules.Jobs/EDMI/ZUGFeRD/ImportZUGFeRDFiles.vb b/Modules.Jobs/EDMI/ZUGFeRD/ImportZUGFeRDFiles.vb
index 328090ac..b8797d48 100644
--- a/Modules.Jobs/EDMI/ZUGFeRD/ImportZUGFeRDFiles.vb
+++ b/Modules.Jobs/EDMI/ZUGFeRD/ImportZUGFeRDFiles.vb
@@ -206,11 +206,24 @@ Public Class ImportZUGFeRDFiles
                                 If Not oFile.Name.EndsWith(".pdf") Then
                                     _logger.Debug("Skipping non-pdf file {0}", oFile.Name)
                                     oEmailAttachmentFiles.Add(oFile)
+
+                                    ' Checking filesize for attachment files
+                                    If Check_FileSize(oFile, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
+                                        _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
+                                        Throw New FileSizeLimitReachedException(oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
+                                    End If
+
                                     Continue For
                                 End If
 
                                 _logger.Info("Start processing file {0}", oFile.Name)
 
+                                ' Checking filesize for pdf files
+                                If Check_FileSize(oFile, oArgs.MaxAttachmentSizeInMegaBytes) = False Then
+                                    _logger.Warn("Filesize for File [{0}] exceeded limit of {1} MB", oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
+                                    Throw New FileSizeLimitReachedException(oFile.Name, oArgs.MaxAttachmentSizeInMegaBytes)
+                                End If
+
                                 Try
                                     oDocument = _zugferd.ExtractZUGFeRDFileWithGDPicture(oFile.FullName)
                                 Catch ex As ZUGFeRDExecption
@@ -241,7 +254,7 @@ Public Class ImportZUGFeRDFiles
                                 End If
 
                                 ' Check the Checksum and rejection status
-                                oMD5CheckSum = Check_MD5Sum(oFile.FullName, oArgs.IgnoreRejectionStatus)
+                                oMD5CheckSum = GenerateAndCheck_MD5Sum(oFile.FullName, oArgs.IgnoreRejectionStatus)
 
                                 ' Check if there are more than one ZUGFeRD files
                                 If oZUGFeRDCount = 1 Then
@@ -334,8 +347,6 @@ Public Class ImportZUGFeRDFiles
                         Catch ex As MD5HashException
                             _logger.Error(ex)
 
-                            'Dim oSQL = $"UPDATE TBEDM_ZUGFERD_HISTORY_IN SET COMMENT = '{oMessage}' WHERE MESSAGE_ID = '{oMessageId}'"
-                            '_firebird.ExecuteNonQuery(oSQL, oFBTransaction)
                             Dim oMessage = "REJECTED - Already processed (MD5Hash)"
                             Update_HistoryEntry(oMessageId, oMD5CheckSum, oMessage, oFBTransaction)
 
@@ -347,9 +358,6 @@ Public Class ImportZUGFeRDFiles
                         Catch ex As InvalidFerdException
                             _logger.Error(ex)
 
-                            'Dim oSQL = $"UPDATE TBEDM_ZUGFERD_HISTORY_IN SET COMMENT = 'REJECTED - ZUGFeRD yes but incorrect format' WHERE GUID = '{HISTORY_ID}'"
-                            '_firebird.ExecuteNonQuery(oSQL, oFBTransaction)
-
                             ' When InvalidFerdException is thrown, we don't have a MD5Hash yet.
                             ' That 's why we set it to String.Empty here.
                             Create_HistoryEntry(oMessageId, String.Empty, "REJECTED - ZUGFeRD yes but incorrect format", oFBTransaction)
@@ -362,8 +370,6 @@ Public Class ImportZUGFeRDFiles
                         Catch ex As TooMuchFerdsException
                             _logger.Error(ex)
 
-                            'Dim oSQL = $"UPDATE TBEDM_ZUGFERD_HISTORY_IN SET COMMENT = 'REJECTED - More than one ZUGFeRD-document in email' WHERE GUID = '{HISTORY_ID}'"
-                            '_firebird.ExecuteNonQuery(oSQL, oFBTransaction)
                             Create_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - More than one ZUGFeRD-document in email", oFBTransaction)
 
                             Dim oBody = EmailStrings.EMAIL_TOO_MUCH_FERDS
@@ -374,8 +380,6 @@ Public Class ImportZUGFeRDFiles
                         Catch ex As NoFerdsException
                             _logger.Error(ex)
 
-                            'Dim oSQL = $"UPDATE TBEDM_ZUGFERD_HISTORY_IN SET COMMENT = 'REJECTED - no ZUGFeRD-Document in email' WHERE GUID = '{HISTORY_ID}'"
-                            '_firebird.ExecuteNonQuery(oSQL, oFBTransaction)
                             Create_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - no ZUGFeRD-Document in email", oFBTransaction)
 
                             Dim oBody = EmailStrings.EMAIL_NO_FERDS
@@ -390,8 +394,7 @@ Public Class ImportZUGFeRDFiles
                             For Each prop In oMissingProperties
                                 oMessage &= $"- {prop}"
                             Next
-                            'Dim oSQL = $"UPDATE TBEDM_ZUGFERD_HISTORY_IN SET COMMENT = 'REJECTED - Missing Required Properties: [{oMessage}]' WHERE GUID = '{HISTORY_ID}'"
-                            '_firebird.ExecuteNonQuery(oSQL, oFBTransaction)
+
                             Create_HistoryEntry(oMessageId, oMD5CheckSum, $"REJECTED - Missing Required Properties: [{oMessage}]", oFBTransaction)
 
                             Dim oBody = CreateBodyForMissingProperties(ex.File.Name, oMissingProperties)
@@ -399,6 +402,17 @@ Public Class ImportZUGFeRDFiles
                             _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "MissingValueException", _EmailOutAccountId)
                             AddRejectedState(oMessageId, "MissingValueException", "Es fehlten ZugferdSpezifikationen", oMessage, oSQLTransaction)
 
+                        Catch ex As FileSizeLimitReachedException
+                            _logger.Error(ex)
+
+                            Create_HistoryEntry(oMessageId, oMD5CheckSum, "REJECTED - File size limit reached", oFBTransaction)
+
+                            Dim oBody = String.Format(EmailStrings.EMAIL_FILE_SIZE_REACHED, oArgs.MaxAttachmentSizeInMegaBytes)
+                            Dim oEmailData = MoveAndRenameEmailToRejected(oArgs, oMessageId)
+
+                            _email.AddToEmailQueueMSSQL(oMessageId, oBody, oEmailData, "FileSizeLimitReachedException", _EmailOutAccountId)
+                            AddRejectedState(oMessageId, "FileSizeLimitReachedException", "Erlaubte Dateigröße überschritten", "", oSQLTransaction)
+
                         Catch ex As OutOfMemoryException
                             _logger.Warn("OutOfMemory Error occurred: {0}", ex.Message)
                             _logger.Error(ex)
@@ -678,7 +692,7 @@ Public Class ImportZUGFeRDFiles
     ''' <param name="pIgnoreRejectionStatus">Should the check take into account the rejection status of the file?</param>
     ''' <returns>The MD5 Checksum of the file, or an empty string, if the Checksum could not be created</returns>
     ''' <exception cref="MD5HashException">Throws, when the file should be rejected, ie. if it already exists in the table</exception>
-    Private Function Check_MD5Sum(pFilePath As String, pIgnoreRejectionStatus As Boolean) As String
+    Private Function GenerateAndCheck_MD5Sum(pFilePath As String, pIgnoreRejectionStatus As Boolean) As String
         Dim oMD5CheckSum = CreateMD5(pFilePath)
 
         ' Exit if MD5 could not be created
@@ -740,4 +754,23 @@ Public Class ImportZUGFeRDFiles
 
         Return oMD5CheckSum
     End Function
+
+    ''' <summary>
+    ''' Checks the size of the supplied file.
+    ''' </summary>
+    ''' <param name="pFileInfo"></param>
+    ''' <param name="pMaxFileSizeInMegaBytes"></param>
+    ''' <returns></returns>
+    Private Function Check_FileSize(pFileInfo As FileInfo, pMaxFileSizeInMegaBytes As Integer) As Boolean
+        If pMaxFileSizeInMegaBytes <= 0 Then
+            Return True
+        End If
+
+        Dim oMaxSize = pMaxFileSizeInMegaBytes * 1024 * 1024
+        If oMaxSize > 0 And pFileInfo.Length > oMaxSize Then
+            Return False
+        Else
+            Return True
+        End If
+    End Function
 End Class
diff --git a/Modules.Jobs/EDMI/ZUGFeRD/WorkerArgs.vb b/Modules.Jobs/EDMI/ZUGFeRD/WorkerArgs.vb
index 32db905e..fc3b7572 100644
--- a/Modules.Jobs/EDMI/ZUGFeRD/WorkerArgs.vb
+++ b/Modules.Jobs/EDMI/ZUGFeRD/WorkerArgs.vb
@@ -13,6 +13,7 @@ Public Class WorkerArgs
 
     Public ExceptionEmailAddress As String
     Public IgnoreRejectionStatus As Boolean
+    Public MaxAttachmentSizeInMegaBytes As Integer
 
     Public Sub New()
         WatchDirectories = New List(Of String)
@@ -26,5 +27,6 @@ Public Class WorkerArgs
 
         ExceptionEmailAddress = Nothing
         IgnoreRejectionStatus = False
+        MaxAttachmentSizeInMegaBytes = -1
     End Sub
 End Class
\ No newline at end of file
diff --git a/Modules.Jobs/Exceptions.vb b/Modules.Jobs/Exceptions.vb
index 894ed27e..a649fe2a 100644
--- a/Modules.Jobs/Exceptions.vb
+++ b/Modules.Jobs/Exceptions.vb
@@ -21,6 +21,14 @@ Public Class Exceptions
         End Sub
     End Class
 
+    Public Class FileSizeLimitReachedException
+        Inherits ApplicationException
+
+        Public Sub New(pFilePath As String, pFileSizeLimitInMegaBytes As Integer)
+            MyBase.New($"At least one file exceeded the filesize limit of {pFileSizeLimitInMegaBytes}MB: {pFilePath}")
+        End Sub
+    End Class
+
     Public Class InvalidFerdException
         Inherits ApplicationException
 
diff --git a/Services.ZUGFeRDService/Config.vb b/Services.ZUGFeRDService/Config.vb
index f0359b1a..3ced11da 100644
--- a/Services.ZUGFeRDService/Config.vb
+++ b/Services.ZUGFeRDService/Config.vb
@@ -21,6 +21,12 @@
         ''' regardless of the REJECTED status.
         ''' </summary>
         Public Property IgnoreRejectionStatus As Boolean = False
+
+        ''' <summary>
+        ''' Maximum Size for attachment files in MB. If This is set to -1,
+        ''' there's no size limit.
+        ''' </summary>
+        Public Property MaxAttachmentSizeInMegaBytes As Integer = -1
     End Class
 
     Public Class FirebirdConfig
diff --git a/Services.ZUGFeRDService/ThreadRunner.vb b/Services.ZUGFeRDService/ThreadRunner.vb
index 8df1a938..79ff2077 100644
--- a/Services.ZUGFeRDService/ThreadRunner.vb
+++ b/Services.ZUGFeRDService/ThreadRunner.vb
@@ -51,7 +51,8 @@ Public Class ThreadRunner
 
         Dim oArgs As New WorkerArgs With {
             .ExceptionEmailAddress = _config.Config.ExceptionEmailAddress,
-            .IgnoreRejectionStatus = _config.Config.Custom.IgnoreRejectionStatus
+            .IgnoreRejectionStatus = _config.Config.Custom.IgnoreRejectionStatus,
+            .MaxAttachmentSizeInMegaBytes = _config.Config.Custom.MaxAttachmentSizeInMegaBytes
         }
         oArgs = LoadFolderConfig(oArgs)
         oArgs = LoadPropertyMapFor(oArgs, "DEFAULT")