Since setting up a new server have been seeing errors like the below which stopped email from being able to be received. Will a swap file solve this as opposed to more RAM?

(01601-18) (!!)file(1) utility (/usr/bin/file) FAILED: run_command: can't fork: Cannot allocate memory at /usr/sbin/amavisd-new line 4850.

==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3.2
- Deployed with iRedMail Easy or the downloadable installer? No
- Linux/BSD distribution name and version: Debian 10
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MariaDB
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====