roundcube return receipts

[Mattia]

when sending return receipts, from the webmail the server sends back the error of wrong configuration of the client as per screenshot.

in the previous version, the error did not occur.

please correct, or recommend a resolution.

thank you

[SH]

fix #752 empty envelope FROM read receipt accept

→ <<cset 6b6c02110323>>

[Mattia]

already corrected in the new version?

how to fix?

[SH]

Issue #745 was marked as a duplicate of this issue.