My email configuration is apparently right, but still I am not able to send emails, through SendGrid, from other places. I think that the problem is about ssl configuration, here is what I find in /var/log/mail.log:Aug 26 13:42:10 google-way postfix/smtpd[6274]: connect from unknown[177.68.227.182]Aug 26 13:42:12 google-way postfix/smtpd[6274]: Anonymous TLS connection established from unknown[177.68.227.182]: TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)Aug 26 13:42:13 google-way postfix/smtpd[6274]: NOQUEUE: reject: RCPT from unknown[177.68.227.182]: 454 4.7.1 <mwdesenvolvimento@gmail.com>: Relay access denied; from=<contato@mwdesenvolvimento.com.br> to=<mwdesenvolvimento@gmail.com> proto=ESMTP helo=<[192.168.1.113]>Here is my postconf -n:alias_database = hash:/etc/aliasesalias_maps = hash:/etc/aliasesappend_dot_mydomain = nobiff = noconfig_directory = /etc/postfixheader_size_limit = 4096000inet_interfaces = allmailbox_size_limit = 0mydestination = localhostmydomain = mwdesenvolvimento.com.brmyhostname = mx.$mydomainmynetworks = 127.0.0.0/8 104.197.230.12 [::ffff:127.0.0.0]/104 [::1]/128myorigin = $mydomainreadme_directory = norecipient_delimiter = +relayhost = [smtp.sendgrid.net]:2525smtp_sasl_auth_enable = yessmtp_sasl_password_maps = hash:/etc/postfix/sasl_passwdsmtp_sasl_security_options = noanonymoussmtp_tls_security_level = encryptsmtp_tls_session_cache_database = btree:${data_directory}/smtp_scachesmtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destinationsmtpd_sasl_path = private/authsmtpd_sasl_type = dovecotsmtpd_tls_CAfile = /etc/ssl/certs/root.mwdesenvolvimento.com.br.crtsmtpd_tls_auth_only = yessmtpd_tls_cert_file = /etc/ssl/certs/mwdesenvolvimento.com.br.crtsmtpd_tls_key_file = /etc/ssl/private/mwdesenvolvimento.com.br.dec.keysmtpd_tls_loglevel = 1smtpd_tls_security_level = maysmtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scachesmtpd_use_tls = yesvirtual_alias_maps = hash:/etc/postfix/virtual_aliasesvirtual_mailbox_domains = $mydomainvirtual_transport = lmtp:unix:private/dovecot-lmtpHere is my doveconf -n:# 2.2.13: /etc/dovecot/dovecot.conf# OS: Linux 3.16.0-4-amd64 x86_64 Debian 8.5 ext4auth_mechanisms = plain loginmail_location = maildir:/var/vmail/%d/%nnamespace inbox {  inbox = yes  location =   mailbox Drafts {    special_use = \Drafts  }  mailbox Junk {    special_use = \Junk  }  mailbox Sent {    special_use = \Sent  }  mailbox Sent Messages {    special_use = \Sent  }  mailbox Trash {    special_use = \Trash  }  prefix = }passdb {  args = scheme=CRYPT username_format=%u /etc/dovecot/users  driver = passwd-file}protocols = imap lmtpservice auth-worker {  user = $default_internal_user}service auth {  unix_listener /var/spool/postfix/private/auth {    group = postfix    mode = 0666    user = postfix  }}service imap-login {  inet_listener imap {    port = 0  }  inet_listener imaps {    port = 993  }}service lmtp {  unix_listener /var/spool/postfix/private/dovecot-lmtp {    group = postfix    mode = 0666    user = postfix  }}ssl = requiredssl_ca = </etc/ssl/certs/root.mwdesenvolvimento.com.br.crtssl_cert = </etc/ssl/certs/mwdesenvolvimento.com.br.crtssl_key = </etc/ssl/private/mwdesenvolvimento.com.br.dec.keyuserdb {  args = uid=vmail gid=vmail home=/var/vmail/%d/%n  driver = static}I am trying to send the email through ThunderBird, without success, as I said before, I think it is not a SendGrid problem, it is not allowing external ip's to send emails only. When I send emails from the server, it works:echo 'Test passed.' | mail -s Test-Email <email>
Postfix with SendGrid 'Relay access denied'
postfix;dovecot