This is the mail system at host mail.zapf.in. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <info(a)fsan-fhl.de&gt;: Host or domain name not found. Name service error for name=fsan-fhl.de type=AAAA: Host not found <fachschaft(a)geoinform.fh-mainz.de&gt;: host ironport-2.zdv.net[134.93.178.242] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fachschaft-skiw(a)aol.com&gt;: host mx-aol.mail.gm0.yahoodns.net[67.195.204.75] said: 554 delivery error: dd No valid recipients found - atlas-production.v2-mail-prod1-bf1.omega.yahoo.com (in reply to end of DATA command) <fachschaft_skiw(a)aol.com&gt;: host mx-aol.mail.gm0.yahoodns.net[67.195.204.75] said: 554 delivery error: dd No valid recipients found - atlas-production.v2-mail-prod1-bf1.omega.yahoo.com (in reply to end of DATA command) <fsr_ff(a)haw-hamburg.de&gt;: host hawhamburg-de0i.mail.protection.outlook.com[104.47.11.138] said: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) (in reply to RCPT TO command) <fsr_hwi(a)haw-hamburg.de&gt;: host hawhamburg-de0i.mail.protection.outlook.com[104.47.11.138] said: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) (in reply to RCPT TO command) <fsr_information(a)haw-hamburg.de&gt;: host hawhamburg-de0i.mail.protection.outlook.com[104.47.11.138] said: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) [FR2DEU01FT008.eop-deu01.prod.protection.outlook.com 2023-11-10T14:02:50.463Z 08DBE134BFA5B2AB] (in reply to RCPT TO command) <fsr_oet(a)haw-hamburg.de&gt;: host hawhamburg-de0i.mail.protection.outlook.com[104.47.11.138] said: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) (in reply to RCPT TO command) <fsr_pug(a)haw-hamburg.de&gt;: host hawhamburg-de0i.mail.protection.outlook.com[104.47.11.138] said: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) [FR2DEU01FT008.eop-deu01.prod.protection.outlook.com 2023-11-10T14:02:50.463Z 08DBE134BFA5B2AB] (in reply to RCPT TO command) <fsr_wirtschaft(a)haw-hamburg.de&gt;: host hawhamburg-de0i.mail.protection.outlook.com[104.47.11.138] said: 550 5.4.1 Recipient address rejected: Access denied. AS(201806281) (in reply to RCPT TO command) <fachschaft-10(a)googlegroups.com&gt;: host gmr-smtp-in.l.google.com[173.194.76.14] said: 550-5.1.1 The email account that you tried to reach does not exist. Please try 550-5.1.1 double-checking the recipient's email address for typos or 550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1 https://support.google.com/mail/?p=NoSuchUser bp17-20020a056512159100b005068bf0b332si1112632lfb.1 - gsmtp (in reply to RCPT TO command) <pfostenloch(a)gmx.net&gt;: host mx01.emig.gmx.net[212.227.17.5] said: 550 Requested action not taken: mailbox unavailable (in reply to RCPT TO command) <fspharma(a)mail.uni-mainz.de&gt;: host mailgate-1.zdv.uni-mainz.de[134.93.178.248] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fsr.geophysik(a)mailman.rrz.uni-hamburg.de&gt;: host mx04.rrz.uni-hamburg.de[134.100.38.104] said: 550 5.1.1 <fsr.geophysik(a)mailman.rrz.uni-hamburg.de&gt;: Recipient address rejected: User unknown in relay recipient table (in reply to RCPT TO command) <fsr_nt(a)haw.hamburg.de&gt;: host mx1.ondataport.de[141.91.162.195] said: 550 5.1.1 <fsr_nt(a)haw.hamburg.de&gt;: Recipient address rejected: User unknown in relay recipient table (in reply to RCPT TO command) <david.weiler(a)stud.ph-gmuend.de&gt;: host mx1.belwue.de[129.143.76.2] said: 577 5.1.1 <david.weiler(a)stud.ph-gmuend.de&gt;: Recipient address rejected: undeliverable address: host mail-hub02.belwue.de[129.143.76.42] said: 577 5.1.1 <david.weiler(a)stud.ph-gmuend.de&gt;: Recipient address rejected: undeliverable address: host mta-in-vm.ph-freiburg.de[193.197.136.98] said: 550 5.1.1 <david.weiler(a)stud.ph-gmuend.de&gt;: Recipient address rejected: User unknown in relay recipient table (in reply to RCPT TO command) (in reply to RCPT TO command) (in reply to RCPT TO command) <suedost.fachschaft(a)geschichte.uni-regensburg.de&gt;: host c2561.mx.srv.dfn.de[194.95.239.17] said: 550 5.1.1 <suedost.fachschaft(a)geschichte.uni-regensburg.de&gt;: Recipient address rejected: undeliverable address: host mx3.uni-regensburg.de[194.94.157.148] said: 550 5.1.1 <suedost.fachschaft(a)geschichte.uni-regensburg.de&gt;: Recipient address rejected: User unknown in virtual alias table (in reply to RCPT TO command) (in reply to RCPT TO command) <fs-wiwi(a)uni.passau.de&gt;: Host or domain name not found. Name service error for name=uni.passau.de type=AAAA: Host not found <frsgeopalmin(a)uni-mainz.de&gt;: host mailgate-1.zdv.uni-mainz.de[134.93.178.248] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fa-fachschaft(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fsfilm(a)uni-mainz.de&gt;: host mailgate-1.zdv.uni-mainz.de[134.93.178.248] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fachschaft-ufpaeda(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fachschaft-zahnmedizin(a)uke.de&gt;: host iplexus1.uke.uni-hamburg.de[134.100.102.32] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fs-archaeologien(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fachschaft-ikb-reha-ezw(a)web.de&gt;: host mx-ha02.web.de[212.227.17.8] said: 550 Requested action not taken: mailbox unavailable (in reply to RCPT TO command) <fachschaft(a)zahni-net.de&gt;: mail for zahni-net.de loops back to myself <fs-judaistik(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fs-musikpaedagogik(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fs-musikvermittlung(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fs-rsl(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <kme-fachschaft(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <rs-rome(a)uni-koeln.de&gt;: host seraph.rrz.uni-koeln.de[134.95.19.134] said: 550 #5.1.0 Address rejected. (in reply to RCPT TO command) <fs-geo(a)uni-landau.de&gt;: host nsmtp.uni-landau.de[139.14.105.152] said: 550 5.1.1 <fs-geo(a)uni-landau.de&gt;: Recipient address rejected: undeliverable address: host dove1.uni-landau.de[139.14.105.143] said: 550 5.1.1 <fs-geo(a)uni-landau.de&gt; User doesn't exist: fs-geo(a)uni-landau.de (in reply to RCPT TO command) (in reply to RCPT TO command) <fsil(a)uni-hildesheim.de&gt;: host robin.uni-hildesheim.de[147.172.16.6] said: 550 Invalid Recipient 3 (in reply to RCPT TO command) <fs-ksa(a)lists.uni-marburg.de&gt;: host a2111.mx.srv.dfn.de[194.95.232.165] said: 550 5.1.1 <fs-ksa(a)lists.uni-marburg.de&gt;: Recipient address rejected: undeliverable address: host vhrz1307.hrz.uni-marburg.de[137.248.1.33] said: 577 5.1.1 <fs-ksa(a)lists.uni-marburg.de&gt;: Recipient address rejected: undeliverable address: host vhrz1432.hrz.uni-marburg.de[137.248.1.90] said: 550 5.1.1 <fs-ksa(a)lists.uni-marburg.de&gt;: Recipient address rejected: User unknown in recipient table (in reply to RCPT TO command) (in reply to RCPT TO command) (in reply to RCPT TO command)