diff --git a/src/FluentEmail.Core/Email.cs b/src/FluentEmail.Core/Email.cs
index 57142656..c066a94e 100644
--- a/src/FluentEmail.Core/Email.cs
+++ b/src/FluentEmail.Core/Email.cs
@@ -461,7 +461,7 @@ public IFluentEmail Attach(IEnumerable<Attachment> attachments)
 
         public IFluentEmail AttachFromFilename(string filename,  string contentType = null, string attachmentName = null)
         {
-            var stream = File.OpenRead(filename);
+            var stream = new MemoryStream(File.ReadAllBytes(filename));
             Attach(new Attachment
             {
                 Data = stream,