Nodemailer

[trasherdk]

The transport.verify().then().catch() thing failing 100% even after successful connection to mail server.
Changing to verify((error, success) => {}) fixed that.

nodemailer.createTransport(options); has an option to control if TLS is required or
if STARTTLS should be tried.

Added SMTP_SECURE option to .env

This is what verify() looks like on the mail server: (followed by what the firewall thinks of things)

: NOQUEUE: connect from client.example.com [1.2.3.144]
: AUTH: available mech=PLAIN, allowed mech=EXTERNAL GSSAPI KERBEROS_V4 DIGEST-MD5 CRAM-MD5
: 13QGhgnj025999: Milter (smf-grey): init success to negotiate
: 13QGhgnj025999: Milter (clamav-milter): init success to negotiate
: 13QGhgnj025999: Milter (smf-spamd): init success to negotiate
: 13QGhgnj025999: Milter: connect to filters
: 13QGhgnj025999: milter=smf-grey, action=connect, accepted
: 13QGhgnj025999: milter=clamav-milter, action=connect, continue
: 13QGhgnj025999: milter=smf-spamd, action=connect, continue
: 13QGhgnj025999: --- 220 mail.example.com ESMTP Sendmail 8.15.2/8.15.2; Mon, 26 Apr 2021 18:43:42 +0200
: 13QGhgnj025999: <-- EHLO [127.0.0.1]
: 13QGhgnj025999: milter=smf-spamd, action=helo, continue
: 13QGhgnj025999: --- 250-mail.example.com Hello client.example.com [1.2.3.144], pleased to meet you
: 13QGhgnj025999: --- 250-ENHANCEDSTATUSCODES
: 13QGhgnj025999: --- 250-PIPELINING
: 13QGhgnj025999: --- 250-8BITMIME
: 13QGhgnj025999: --- 250-SIZE
: 13QGhgnj025999: --- 250-DSN
: 13QGhgnj025999: --- 250-ETRN
: 13QGhgnj025999: --- 250-STARTTLS
: 13QGhgnj025999: --- 250-DELIVERBY
: 13QGhgnj025999: --- 250 HELP
: 13QGhgnj025999: <-- STARTTLS
: 13QGhgnj025999: --- 220 2.0.0 Ready to start TLS
: STARTTLS: x509 cert verify: depth=0 /C=DK/ST=Denmark/L=Copenhagen/O=Example/OU=Mailserver Cert/CN=mail.example.com/emailAddress=hostmaster@example.com, state=0, reason=unable to get certificate CRL
: STARTTLS: x509 cert verify: depth=1 /C=DK/ST=Denmark/L=Copenhagen/O=Example Corp/OU=Certification Services Division/CN=Example Corp Root CA/emailAddress=hostmaster@example.com, state=0, reason=unable to get certificate CRL
: STARTTLS=server, get_verify: 0 get_peer: 0x0
: STARTTLS=server, relay=client.example.com [1.2.3.144], version=TLSv1.2, verify=NO, cipher=DHE-RSA-AES128-GCM-SHA256, bits=128/128
: STARTTLS=server, cert-subject=, cert-issuer=, verifymsg=ok
: AUTH: available mech=PLAIN, allowed mech=EXTERNAL GSSAPI KERBEROS_V4 DIGEST-MD5 CRAM-MD5
: STARTTLS=read, info: fds=9/3, err=2
: 13QGhgnj025999: --- 421 4.4.1 mail.example.com Lost input channel from client.example.com [1.2.3.144]
: 13QGhgnj025999: client.example.com [1.2.3.144] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA

The firewall does not like the way nodemailer behaves, but this connecting client is whitelisted

: Enter dbcheckwhitelist: 1.2.3.144 
: Blacklist IP: 1.2.3.144 - MAIL/EXPN/VRFY/ETRN 
: Enter dbblacklist: 1.2.3.144 - MAIL/EXPN/VRFY/ETRN 
: LOCALNET: Whitelisted host at 1.2.3.144 -- NOT BLACKLISTING 

[trasherdk]

A refactored version, reverting to verify().then().catch() chaining, by adding the missing tls.rejectUnauthorized setting.

[hagopj13]

Thanks for your PR. And sorry for the late review, I was really busy these days, but now I'm back to occasionally working on the boilerplate.

Please see the minor changes that I requested. Also, can you solve merge conflicts and remove the package-lock.json (we're using yarn.lock)?

[trasherdk]

Latest push only contain the changes in functionality.
I don't use yarn, so it's capabilities are unknown to me. npm on the other hand, is capable of updating yarn.lock,
keeping both lock files in sync.