Host Error after crontab update(letsencrypt renewal)

Hello. I’m using vultr.com to host https address,
running wordpress on vultr.com and server runs on ubuntu 16.04.

Here’s my setup for nginx, certbot and crontab to auto renew letsencrypt.

# nginx installation

commandline
sudo add-apt-repository ppa:certbot/certbot
sudo apt update
sudo apt install -y python-certbot-nginx

# nginx configuration
  '/etc/nginx/site-available/default' is referenced by '/etc/nginx/nginx.conf'

# /etc/nginx/nginx.conf
user  nginx;
worker_processes  1;

error_log  /var/log/nginx/error.log warn;
pid        /var/run/nginx.pid;

events {
       worker_connections 1024;
}

http {
  include /etc/nginx/mime.types;
  default_type application/octet-stream;
  log_format main '$remote_addr - $remote_user [...omitted...] "";
  access_log /var/log/nginx/access.log main;
  sendfile on;
  #tcp_nopush on;
  
  keepalive_timeout 65;
  #gzip on;
  include /etc/nginx/sites-available/default;
}

# crontab -e
# the following commands scheduled 1st and 20th of every month at 12:10 PM
  10 12 1, 20 * * /usr/bin/letsencrypt renew >> /var/log/le-renew.log
  11 12 1, 20 * * /bin/systemctl reload nginx

# /etc/nginx/sites-available/default
server {
    listen         80 default_server;
    listen         [::]:80 default_server;
    server_name    DOMAINNAME.net www.DOMAINNAME.net;
    return 301 https://$server_name$request_url;
}
server {
    listen         443 ssl http2 default_server;
    listen         [::]:443 ssl http2 default_server;

    # ssl parameters & ssl_certificates
    include /etc/nginx/snippets/ssl-DOMAINNAME.net.conf;
    include /etc/nginx/snippets/ssl-params.conf;

    root           /var/www/html/;
    index index.php;
    
    location {...}
}

Letsencrypt certification is renewed successfully.
The problem is, however, whenever crontab executes scheduled task of letsencrypt renewal, the Email Log shows Error messages:

'' does not match the expected structure for a DNS hostname, '' does not appear to be a valid URI hostname, '' does not appear to be a valid local network name.

Another problem is whenever users posts a content or reply, the loading/refresh takes forever even though the data transaction works just fine(e.g. post is successfully posted.)

Here’s the result of WordPress plugin Post SMTP (by Yehuda Hassine) “Connectivity Test”
:

Transport	Socket	Status*	Service Available	Server ID	Authentication
None	Login	Plain	CRAM-MD5	OAuth 2.0
SMTP	smtp.gmail.com:25	Closed	No	-	-	-	-	-	-
SMTP	smtp.gmail.com:465	Open	🔒 SMTPS	gmail.com	No	Yes	Yes	No	Yes
SMTP	smtp.gmail.com:587	Open	🔒 SMTP-STARTTLS	gmail.com	No	Yes	Yes	No	Yes
Mandrill API	mandrillapp.com:443	Open	🔒 HTTPS	mandrillapp.com	n/a
SendGrid API	api.sendgrid.com:443	Open	🔒 HTTPS	sendgrid.com	n/a
Mailgun API	api.mailgun.net:443	Open	🔒 HTTPS	mailgun.net	n/a
* According to portquiz.net

Summary:
✅ 🔒 Port 443 can be used with the SendGrid API.
✅ 🔒 Port 443 can be used with the Gmail API.
✅ 🔒 Port 443 can be used with the Mailgun API.
✅ 🔒 Port 587 can be used for SMTP to smtp.gmail.com.
✅ 🔒 Port 443 can be used with the Mandrill API.
✅ 🔒 Port 465 can be used for SMTP to smtp.gmail.com.
❌ No outbound route between this site and the Internet on Port 25.
A test with "No" Service Available indicates one or more of these issues:

Your web host has placed a firewall between this site and the Internet
The SMTP hostname is wrong or the mail server does not provide service on this port
Your PHP configuration is preventing outbound connections
Your WordPress configuration is preventing outbound connections

I’d appreciate for any clues. Thanks.

• This topic was modified 6 years, 3 months ago by jnuho.
• This topic was modified 6 years, 3 months ago by Marius L. J.. Reason: Format log outputs for readability

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