我试图安装sendmail在Ubuntu 16 中，但在尝试生成ssl证书时挂起了无法继续下去。我取消了安装过程，后来杀死了正在锁定任何新软件包的进程；

这个时候我甚至无法安装其他软件 安装时提示 sudo dpkg --configure -a
CLI Information

sudo dpkg --configure -a
Setting up sendmail-bin (8.15.2-3) ...
Updating sendmail environment ...
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Writing configuration to /etc/mail/sendmail.conf.
Writing /etc/cron.d/sendmail.
Disabling HOST statistics file(/var/lib/sendmail/host_status).
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Writing configuration to /etc/mail/sendmail.conf.
Writing /etc/cron.d/sendmail.
Could not open /etc/mail/databases(No such file or directory), creating it.
Reading configuration from /etc/mail/sendmail.conf.
Validating configuration.
Creating /etc/mail/databases...

Checking filesystem, this may take some time - it will not hang!
... Done.

Checking for installed MDAs...
sasl2-bin not installed, not configuring sendmail support.

To enable sendmail SASL2 support at a later date, invoke "/usr/share/sendmail/update_auth"

Creating/Updating SSL(for TLS) information
Creating /etc/mail/tls/starttls.m4...
Creating SSL certificates for sendmail.

解决方法

I just experienced this problem also. It appears to hang on line 240 of this script

/usr/share/sendmail/update_tls.

To solve the problem, I executed the following commands:

cd /etc/mail/tls
sudo openssl dsaparam -out sendmail-common.prm 2048
sudo chown root:smmsp sendmail-common.prm
sudo chmod 0640 sendmail-common.prm
sudo dpkg --configure -a