postfix errors fatal: no SASL authentication mechanisms /usr/libexec/postfix/smtpd: bad command startup -- throttling solution

Jul  3 22:12:17mailserver postfix/smtpd[6195]: fatal: no SASL authentication mechanisms
Jul  3 22:12:18mailserver postfix/master[4881]: warning: process /usr/libexec/postfix/smtpd pid 6195 exit status 1
Jul  3 22:12:18mailserver postfix/master[4881]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling

This only ever happens in my experience when the authentication method is actually Dovecot.  Usually the problem will be that Dovecot cannot start due to a misconfiguration and or permissions issue. 

The solution is to try to trace through /var/log/maillog and find out what is wrong with Dovecot (assuming it cannot start).

After this postfix should work fine.

You should also enable debug info in dovecot.conf like this:

auth_debug = yes
auth_debug_passwords = yes
auth_verbose = yes

To give you an idea of what commonly goes wrong after a new Dovecot migration or install:

dovecot: auth: Error: passwd-file /etc/dovecot.passwd: open(/etc/dovecot.passwd) failed: Permission denied (euid=97(dovecot) egid=97(dovecot) missing +r perm: /etc/dovecot.passwd, euid is not dir owner)

Solution:

chmod +x /etc/dovecot.passwd

Another error:

dovecot: lda: Error: userdb lookup: connect(/var/run/dovecot/auth-userdb) failed: Connection refused

In this case you need to make sure /var/run/dovecot/auth-userdb and also /var/mail is set to the correct user id and group id or username/groupname as in your /etc/dovecot/dovecot.conf

first_valid_gid = 502
first_valid_uid = 501
last_valid_gid = 502
last_valid_uid = 501

 


Tags:

postfix, errors, fatal, sasl, authentication, mechanisms, usr, libexec, smtpd, startup, throttling, solutionjul, mailserver, jul, pid, method, dovecot, misconfiguration, permissions, var, maillog, enable, debug, info, conf, auth_debug, auth_debug_passwords, auth_verbose, commonly, migration, install, auth, passwd, etc, euid, egid, perm, dir, chmod, lda, userdb, lookup, user, username, groupname, first_valid_gid, first_valid_uid, last_valid_gid, last_valid_uid,

Latest Articles

  • qemu: could not load PC BIOS 'bios-256k.bin' solution
  • Proxmox How To Custom Partition During Install
  • Hyper-V Linux VM Boots to Black Screen, Storage, NIC Not Found Issues
  • Ubuntu Mint How to Fix Missing/Broken /dev and /dev/pts which causes terminal to immediately close exit and not work
  • How high can a Xeon CPU get?
  • bash fix PATH environment variable "command not found" solution
  • Ubuntu Linux Mint Debian Redhat Youtube Cannot Play HD or 4K videos, dropped frames or high CPU usage with Nvidia or AMD Driver
  • hostapd example configuration for high speed AC on 5GHz using WPA2
  • hostapd how to enable and use WPS to connect wireless devices like printers
  • Dell Server Workstation iDRAC Dead after Firmware Update Solution R720, R320, R730
  • Cloned VM/Server/Computer in Linux won't boot and goes to initramfs busybox Solution
  • How To Add Windows 7 8 10 11 to GRUB Boot List Dual Booting
  • How to configure OpenDKIM on Linux with Postfix and setup bind zonefile
  • Debian Ubuntu 10/11/12 Linux how to get tftpd-hpa server setup tutorial
  • efibootmgr: option requires an argument -- 'd' efibootmgr version 15 grub-install.real: error: efibootmgr failed to register the boot entry: Operation not permitted.
  • Apache Error Won't start SSL Cert Issue Solution Unable to configure verify locations for client authentication SSL Library Error: 151441510 error:0906D066:PEM routines:PEM_read_bio:bad end line SSL Library Error: 185090057 error:0B084009:x509 certif
  • Linux Debian Mint Ubuntu Bridge br0 gets random IP
  • redis requirements
  • How to kill a docker swarm
  • docker swarm silly issues