As I already wrote in a post in May 2010, Switzerland's biggest Internet Provider (Swisscom) doesn't allow to use port 25 to send e-mail anymore (except when using Swisscom's SMTP servers).
The interception can be seen with a simple telnet to the web server of my website (area-1.ch):
telnet area-1.ch 25
220 zhhdzmsp-nwas18.bluewin.ch ESMTP Service (Swisscom Schweiz AG) ready
helo this-isnt-right.ch
250 zhhdzmsp-nwas18 says HELO to 83.77.40.89:49765
Instead of area-1.ch, the response comes from zhhdzmsp-nwas18.bluewin.ch. Clearly an interception (or port forwarding on the provider site).
For all independent web hosters this is such a pain, and even more for their customers as they must manually switch the SMTP port in their mail clients.
No comments yet.
AWS Android Ansible Apache Apple Atlassian BSD Backup Bash Bluecoat CMS Chef Cloud Coding Consul Containers CouchDB DB DNS Database Databases Docker ELK Elasticsearch Filebeat FreeBSD Galera Git GlusterFS Grafana Graphics HAProxy HTML Hacks Hardware Icinga Influx Internet Java KVM Kibana Kodi Kubernetes LVM LXC Linux Logstash Mac Macintosh Mail MariaDB Minio MongoDB Monitoring Multimedia MySQL NFS Nagios Network Nginx OSSEC OTRS Office PGSQL PHP Perl Personal PostgreSQL Postgres PowerDNS Proxmox Proxy Python Rancher Rant Redis Roundcube SSL Samba Seafile Security Shell SmartOS Solaris Surveillance Systemd TLS Tomcat Ubuntu Unix VMWare VMware Varnish Virtualization Windows Wireless Wordpress Wyse ZFS Zoneminder