diff --git a/internal/smtp/user.go b/internal/smtp/user.go
index caed8442..5b4901b4 100644
--- a/internal/smtp/user.go
+++ b/internal/smtp/user.go
@@ -21,6 +21,7 @@ package smtp
 
 import (
 	"encoding/base64"
+	"fmt"
 	"io"
 	"mime"
 	"net/mail"
@@ -179,7 +180,7 @@ func (su *smtpUser) Send(from string, to []string, messageReader io.Reader) (err
 			return err
 		}
 
-		attachedPublicKeyName = "publickey - " + kr.GetIdentities()[0].Name
+		attachedPublicKeyName = fmt.Sprintf("publickey - %v - %v", kr.GetIdentities()[0].Name, firstKey.GetFingerprint())
 	}
 
 	message, mimeBody, plainBody, attReaders, err := message.Parse(messageReader, attachedPublicKey, attachedPublicKeyName)
diff --git a/internal/store/user_message.go b/internal/store/user_message.go
index 7ea629e1..e85a8322 100644
--- a/internal/store/user_message.go
+++ b/internal/store/user_message.go
@@ -63,7 +63,7 @@ func (store *Store) CreateDraft(
 		attachmentReaders = append(attachmentReaders, strings.NewReader(attachedPublicKey))
 		publicKeyAttachment := &pmapi.Attachment{
 			Name:     attachedPublicKeyName + ".asc",
-			MIMEType: "application/pgp-key",
+			MIMEType: "application/pgp-keys",
 			Header:   textproto.MIMEHeader{},
 		}
 		attachments = append(attachments, publicKeyAttachment)
diff --git a/pkg/message/parser.go b/pkg/message/parser.go
index cd64ad79..db4c6d39 100644
--- a/pkg/message/parser.go
+++ b/pkg/message/parser.go
@@ -348,8 +348,8 @@ func getPlainBody(part *parser.Part) []byte {
 func attachPublicKey(p *parser.Part, key, keyName string) error {
 	h := message.Header{}
 
-	h.Set("Content-Type", fmt.Sprintf(`application/pgp-key; name="%v"`, keyName))
-	h.Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%v.asc.pgp"`, keyName))
+	h.Set("Content-Type", fmt.Sprintf(`application/pgp-keys; name="%v.asc"; filename="%v.asc"`, keyName, keyName))
+	h.Set("Content-Disposition", fmt.Sprintf(`attachment; name="%v.asc"; filename="%v.asc"`, keyName, keyName))
 	h.Set("Content-Transfer-Encoding", "base64")
 
 	body := new(bytes.Buffer)