When trying to upgrade our ftpsync installation to the latest one
downloaded via git we noticed that error emails sent by the new
version are shown as invalid by some mail readers.

This is caused by not quoting the boundary value in the MIME header.

The following patch fixes this problem (any tab characters are likely
mangled to regular spaces):

diff --git a/bin/common b/bin/common
index 7f3cc50..f4f4d94 100644
--- a/bin/common
+++ b/bin/common
@@ -389,7 +389,7 @@ Subject: ${subject}
  To: $(join_by ', ' "$@")
  Auto-Submitted: auto-generated
  MIME-Version: 1.0
-Content-Type: multipart/mixed; boundary=${boundary}
+Content-Type: multipart/mixed; boundary="${boundary}"

  EOF
          if [[ ${body[@]:-} ]]; then

Hi,

I have attached a more complete patch which fixes some more encoding
errors.

Cheers,

Hi,

thanks for the patch.

This line seems wrong, I assume it's meant to be
Content-Transfer-Encoding?  Also probably needs to come somewhere other
than after the attachment?

Cheers,
Julien