在执行
sudo apt-get install -y lsb-release wget # optional
codename=`lsb_release -c -s`
sudo mkdir -p /etc/apt/keyrings
wget -o- https://rspamd.com/apt-stable/gpg.key | gpg --dearmor | sudo tee /etc/apt/keyrings/rspamd.gpg > /dev/null
echo "deb [arch=amd64 signed-by=/etc/apt/keyrings/rspamd.gpg] http://rspamd.com/apt-stable/ $codename main" | sudo tee /etc/apt/sources.list.d/rspamd.list
echo "deb-src [arch=amd64 signed-by=/etc/apt/keyrings/rspamd.gpg] http://rspamd.com/apt-stable/ $codename main" | sudo tee -a /etc/apt/sources.list.d/rspamd.list
sudo apt-get update
sudo apt-get --no-install-recommends install rspamd
即可解决