---
title: Certificates 
menu:
  main:
    parent: Nerdstuff
---

## Retrieve certificate information from server

### HTTPS

```
openssl s_client -connect mail.br0tkasten.de:443 -servername mail.br0tkasten.de </dev/null 2>/dev/null | openssl x509 -noout -text
```

### IMAP with STARTTLS
```
openssl s_client -starttls imap -connect mail.br0tkasten.de:143 </dev/null 2>/dev/null | openssl x509 -noout -text
```

### SMTP with STARTTLS
```
openssl s_client -starttls smtp -connect mail.br0tkasten.de:587 </dev/null 2>/dev/null | openssl x509 -noout -text
```