diff --git a/Sources/SwiftSMTP/Mail.swift b/Sources/SwiftSMTP/Mail.swift
index 3f34df3..5ecd602 100644
--- a/Sources/SwiftSMTP/Mail.swift
+++ b/Sources/SwiftSMTP/Mail.swift
@@ -124,6 +124,10 @@ public struct Mail {
         dictionary["FROM"] = from.mime
         dictionary["TO"] = to.map { $0.mime }.joined(separator: ", ")
 
+        if !bcc.isEmpty {
+            dictionary["BCC"] = bcc.map { $0.mime }.joined(separator: ", ")
+        }
+        
         if !cc.isEmpty {
             dictionary["CC"] = cc.map { $0.mime }.joined(separator: ", ")
         }