Fix some external links

doc/modules/clickhouse.md

@@ -156,7 +156,7 @@ retention {
 }
 ~~~
 
-To remove data for particular users, you might consider using of the [Clickhouse mutations](https://clickhouse.com/docs/en/sql-reference/statements/alter#alter-mutations)
+To remove data for particular users, you might consider using of the [Clickhouse mutations](https://clickhouse.com/docs/en/sql-reference/statements/alter#mutations)
 
 ### Subject privacy
 

doc/modules/external_services.md

@@ -768,7 +768,7 @@ spamassassin {
 
 ## Virustotal details
 
-To receive results, Rspamd utilizes the [`file/report`](https://developers.virustotal.com/reference#file-report) endpoint of Virustotal. However, due to the strict policies of Virustotal, it is crucial that you have set your own key in the plugin configuration:
+To receive results, Rspamd utilizes the [`file/report`](https://virustotal.readme.io/v2.0/reference/file-report) endpoint of Virustotal. However, due to the strict policies of Virustotal, it is crucial that you have set your own key in the plugin configuration:
 
 ~~~hcl
 # local.d/antivirus.conf

doc/other/usage_policy.md

@@ -27,7 +27,7 @@ If you qualify (1) and (2) but still got blocked then please contact us by using
 
 Rspamd map checks typically run quietly in the background. When servers are selected, they will usually stay in the configuration indefinitely. If the client traffic causes problems for the server, it can be difficult to address if not carefully planned for in advance.
 
-For example, there was an [incident](https://www.reddit.com/r/synology/comments/f5jczp/mailplus_server_and_rspamdcom/) that caused troubles for both Rspamd project and the vendor's users.
+For example, there was an [incident](https://www.reddit.com/r/synology/comments/f5jczp/mailplus_server_and_rspamdcom/?rdt=48389) that caused troubles for both Rspamd project and the vendor's users.
 
 Hence, we are kindly asking to [contact us](mailto:[email protected]) before embedding Rspamd in any sort of commercial or open source project. In this way, we could decide about the strategy to avoid issues with the embedded solution in future.
 

downloads.md

@@ -184,7 +184,7 @@ FreeBSD users can install Rspamd from [ports](https://www.freshports.org/mail/rs
 
 Users of NetBSD (and other systems with pkgsrc) can use [pkgsrc](https://pkgsrc.se/mail/rspamd).
 
-OpenBSD users can use [ports](https://openports.se/mail/rspamd).
+OpenBSD users can use [ports](https://openports.pl/path/mail/rspamd).
 
 macOS users can install from [MacPorts](https://ports.macports.org/port/rspamd):
 ```