If you receive a suspicious email from someone you know, how can you pre-test?
You can confirm through other channels (e.g. phone, WhatsApp, etc.)
If the email has other contents, such as attachments or links, you can –
[Scan attachments and URL]
If it is not confidential, you can upload it to VirusTotal.com for detection.
[Preview URL links]
You can try some free/trial website screenshot services (for example: Screenshot Guru, Screenshot Machine, etc.) to preview the website before you decide whether to use your own computer to browse it.