I'm having problem with receiving emails from Gmail. The problem is gmail only. I can send mails to gmail and receive it perfectly in gmail. I also being able to receive mails from yahoo and other custom domain. On the gmail side, it says the message was sent successfully but I can not receive it. Can anyone help me please. Here is the detail of the error log

Dec 19 09:39:03 serverubuntu postfix/smtpd[8400]: connect from mail-wm0-f47.google.com[]

Dec 19 09:39:04 serverubuntu postfix/smtpd[8400]: SSL_accept error from mail-wm0-f47.google.com[]: -1

Dec 19 09:39:04 serverubuntu postfix/smtpd[8400]: warning: TLS library problem: error:04075070:rsa routines:RSA_sign:digest too big for rsa key:rsa_sign.c:122:

Dec 19 09:39:04 serverubuntu postfix/smtpd[8400]: warning: TLS library problem: error:1409B006:SSL routines:ssl3_send_server_key_exchange:EVP lib:s3_srvr.c:1996:

Dec 19 09:39:04 serverubuntu postfix/smtpd[8400]: lost connection after STARTTLS from mail-wm0-f47.google.com[]

Dec 19 09:39:04 serverubuntu postfix/smtpd[8400]: disconnect from mail-wm0-f47.google.com[]

And here is my Postfix main.cf file

smtpd_data_restrictions = reject_unauth_pipelining

smtpd_reject_unlisted_recipient = yes

smtpd_reject_unlisted_sender = yes

smtpd_tls_protocols = !SSLv2 !SSLv3

smtp_tls_protocols = !SSLv2 !SSLv3

lmtp_tls_protocols = !SSLv2 !SSLv3

smtpd_tls_mandatory_protocols = !SSLv2 !SSLv3

smtp_tls_mandatory_protocols = !SSLv2 !SSLv3

lmtp_tls_mandatory_protocols = !SSLv2 !SSLv3

smtpd_tls_mandatory_exclude_ciphers = aNULL, eNULL, EXPORT, DES, RC4, MD5, PSK, aECDH, EDH-DSS-DES-CBC3-SHA, EDH-RSA-DES-CDC3-SHA, KRB5-DE5, CBC3-SHA

smtpd_tls_dh1024_param_file = /etc/ssl/dhparams.pem

smtp_tls_security_level = may

smtp_tls_CAfile = $smtpd_tls_CAfile

smtp_tls_loglevel = 0

smtp_tls_note_starttls_offer = yes

smtpd_sender_restrictions = reject_unknown_sender_domain, reject_non_fqdn_sender, reject_unlisted_sender, permit_mynetworks, reject_sender_login_mismatch, permit_sasl_authenticated

Thanks in advance

1 Answer 1


Your server is probably presenting a client certificate that's too small for Gmail's liking. It might be using the Ubuntu snakeoil key. Check to see what your private key postfix is using says with: openssl rsa -in private.key -text -noout

Regenerate a rsa keypair to 1024 or 2048 and use that.

  • Problem solved. It is indeed certificate problem. I have replaced it with new certificate that i have generated tools/generate_ssl_keys.sh' in iRedMail-0.9.3 and now all the gmail messages can be received normally. All the pending mails i have sent from gmail is now starting to come in one by one
    – pasaisea
    Dec 19, 2015 at 3:59

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