5.1.7 Invalid sender address syntax when asking for notification
when sending mail with notication to provider KPN I get an 5.1.7 Invalid sender address syntax when sending without notification of recieving no problems what to do?
Chosen solution
I heard about an undocumented solution: using mail.planet.nl, port 25, ssl, no username (!) all working again
Read this answer in context 👍 0All Replies (2)
and I checked my sent mail header looking at the source of the message: there is no "Return-Receipt-To" ??? From - Mon Dec 12 06:22:20 2016 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00800000 X-Mozilla-Keys: To: xxx@xxxxx.nl From: bbb <bbbbbb@planet.nl> Subject: test Message-ID: <f75a421a-b35f-4852-20de-316c3bf2f816@planet.nl> Date: Mon, 12 Dec 2016 06:22:19 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101
Thunderbird/45.5.1
MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit
Seçilmiş Həll
I heard about an undocumented solution: using mail.planet.nl, port 25, ssl, no username (!) all working again