Credits

Images

sms https://pixabay.com/vectors/message-sms-text-computer-button-150459/ (Free for commercial use, no attribution required)

caution https://pixabay.com/vectors/sign-caution-warning-danger-safety-304093/ (Free for commercial use, No attribution required)

radio https://pixabay.com/vectors/broadcast-tower-radio-wave-297434/ (Free for commercial use, No attribution required)

radio https://vector.me/browse/109677/antenna_and_radio_waves_clip_art (https://vector.me/, by johnpwarren)

exchange https://commons.wikimedia.org/wiki/File:Microsoft_Exchange_(2019-present).svg (Wikimedia)

postfix https://commons.wikimedia.org/wiki/File:Postfix-logo.svg (Wikimedia)