update content from old pull requests

content/2.getting-started/1.prerequisites.md

@@ -13,7 +13,7 @@ We **strongly** recommend installing Postal on its own dedicated server (i.e. a
 
 * At least 4GB of RAM
 * At least 2 CPU cores
-* At least 100GB of disk space
+* An appropriate amount of disk space (at least 25GB) for your use case
 
 Most people install Postal on virtual servers. There are lots of providers to choose from including [Digital Ocean](https://m.do.co/c/17696597a9ed) and [Linode](https://www.linode.com).
 

content/2.getting-started/5.upgrade-to-v2.md

@@ -159,8 +159,9 @@ If you want to simply install Postal on a new server and copy your data over, yo
 2. On your old server, stop Postal using `postal stop`. Make sure it has fully stopped before continuing using `postal status`.
 3. On your new server, stop Postal using `postal stop`.
 4. Use whatever tool takes your fancy (`mysqldump`, `Mariabackup` etc...) to copy your databases to your new server. Make sure you copy the `postal` database as well as all other databases prefixed with `postal` (or whatever you have configured your prefix to be in the `message_db` part of your configuration).
-5. Ensure that your `postal.yml` is merged appropriately. For example, make sure your `dns` section is correct. There is no need to copy the `rails.secret` - a new secret on the new host won't be a problem.
-6. If you stopped Postal cleanly before beginning, there is no need to copy any persisted data from RabbitMQ.
-7. Shutdown your old Postal server.
-8. Move the IP address(es) from the old server to the new one (if both old and new servers are with the same provider).
-9. Start Postal on the new server using `postal start`.
+5. On your new server, run `postal upgrade-db` to update the copied database with the changed table structures
+6. Ensure that your `postal.yml` is merged appropriately. For example, make sure your `dns` section is correct. There is no need to copy the `rails.secret` - a new secret on the new host won't be a problem.
+7. If you stopped Postal cleanly before beginning, there is no need to copy any persisted data from RabbitMQ.
+8. Shutdown your old Postal server.
+9. Move the IP address(es) from the old server to the new one (if both old and new servers are with the same provider).
+10. Start Postal on the new server using `postal start`.

content/3.features/spam-and-virus-checking.md

@@ -20,7 +20,13 @@ By default, Postal will talk to SpamAssassin's `spamd` using an TCP socket conne
 sudo apt install spamassassin
 ```
 
-Once you have installed this, you will need to open up `/etc/default/spamassassin` and change `ENABLED` to `1` and  `CRON` to `1`. Then you should restart SpamAssassin.
+Once you have installed this, you will need to open up `/etc/default/spamassassin` and change `ENABLED` to `1` and  `CRON` to `1`. On some systems (such as Ubuntu 20.04 or newer), you might need to enable the SpamAssassin daemon with the following command.
+
+```bash
+update-rc.d spamassassin enable 
+```
+
+Then you should restart SpamAssassin.
 
 ```
 sudo systemctl restart spamassassin

content/5.other/2.containers.md

@@ -70,7 +70,7 @@ openssl genrsa -out path/to/signing.key 2018
 
 ## Networking
 
-If you wish to utilise IP pools, you will need to run Postal using host networking. This is because Postal will need to be able to determine which physical IPs are available to it and be able to send and receiving traffic on those IPs.
+If you wish to utilise IP pools, you will need to run Postal using host networking. This is because Postal will need to be able to determine which physical IPs are available to it and be able to send and receive traffic on those IPs.
 
 If you are not using IP pools, there is no need to use host networking and you can expose the ports listed above as appropriate.