2018年12月14日 · Send-Mailmessage : The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Must issue a STARTTLS command first. The PowerShell documentation says adding -UseSSL should specify that a STARTTLS command be sent, but even adding this flag may not resolve your issues. Command:

explicitly calling .starttls() on smtp servers supporting it with a malicious MitM stripping your STARTTLS command and forging a non 220 response will NOT negotiate ssl, nor raise an exception and therefore leave your communication unencrypted - ergo it is vulnerable to striptls unless you manually verify that the response to .starttls()[0 ...

2014年11月20日 · openssl s_client -debug -starttls smtp -crlf -connect localhost:25 OpenSSL will do the STARTTLS handshake for you and you will be able to pick up the conversation from there (decrypted automatically on the fly).

2015年9月19日 · openssl s_client -starttls smtp -4 -connect smtp.server.no:587 -crlf -ign_eof -4 can be needed to force IPv4. If from command line on Windows, one should not use the -crlf option. E.g: openssl s_client -starttls smtp -4 -connect smtp.server.no:587 -ign_eof Hello. On successful connection and the welcoming 250 HELP do the normal EHLO: EHLO nero ...

2012年5月9日 · So try to set it (boolean) true like props.put("mail.smtp.starttls.enable", true); or if its dynamic then make sure your variable is boolean or if its String then db value should be set as true. Share

2016年4月20日 · In this mode, the SMTP session begins on an unencrypted channel, then a STARTTLS command is issued by the client to the server to switch to secure communication using SSL. See RFC 3207 published by the Internet …

2016年9月6日 · I am trying to send email through gmail via postfix, but it shows me the following error: Must issue a STARTTLS command first. Sep 6 01:11:34 NovusTec postfix/smtp[10889]: 1284460D68: to=<cassa@

2009年1月4日 · If you forget props.put("mail.smtp.starttls.enable","true") you get com.sun.mail.smtp.SMTPSendFailedException: 451 5.7.3 STARTTLS is required to send mail. If you forget props.put("mail.smtp.ssl.protocols", "TLSv1.2"); you get javax.mail.MessagingException: Could not convert socket to TLS; and No appropriate protocol …

2011年10月11日 · smtp.gmail.com forces you to use an encrypted connection using STARTTLS. Indy 9 does not support STARTTLS directly, but indy 10 does. In Indy 10, before connecting to the server, you have to assign an SSL-enabled IOHandler, such as TIdSSLIOHandlerSocketOpenSSL,

please post the snippet of your mail sending code. maybe it's just enough to remove "server.starttls()", but difficult to tell without the code – Gryphius Commented Jun 15, 2011 at 9:18