SMTP, the Simple Mail Transfer Protocol, is the standard set of rules that email servers use to send messages to one another. Every email sent from Ghana, whether from a Gmail account in Accra, a university’s Outlook server in Legon or a fintech app hosted abroad, uses SMTP at some point on its journey.
How an email travels
- Submission. Your email client or application connects to an outgoing SMTP server and hands over the message, usually after logging in.
- Lookup. The SMTP server checks the recipient’s domain in the DNS to find its mail server (the MX record).
- Transfer. The sending server connects to the receiving server and transfers the message using SMTP commands.
- Checks. The receiving server checks authentication, reputation and content before deciding between inbox, spam folder or rejection.
- Delivery. The recipient reads the message using another protocol, such as IMAP, on their phone or computer.
Ports and security
SMTP submission normally uses port 587 with STARTTLS, or port 465 with implicit TLS. Port 25 is used between servers and is often blocked by internet providers for ordinary users to reduce spam. Mailpro encrypts connections with TLS 1.3.
Authentication: SPF, DKIM and DMARC
Because SMTP was designed in an era of trust, it does not verify senders by itself. Three DNS-based standards fill the gap:
- SPF lists the servers allowed to send for your domain.
- DKIM adds a cryptographic signature to each message.
- DMARC tells receivers what to do when checks fail, and sends you reports.
For Ghanaian organisations, especially banks, telcos and mobile-money brands that are frequent targets of impersonation, these are essential. See DMARC record set-up in Mailpro.
When you need an SMTP relay
If your website or application sends email, you need an SMTP server. Using your hosting provider’s shared server is possible but often leads to spam-folder placement. A professional relay such as Mailpro’s SMTP server for Ghana handles authentication, reputation and reporting for you.
Common SMTP errors you may see
- 535 Authentication failed: wrong username or password in your application settings.
- 550 Mailbox unavailable: the address does not exist; remove it from your list.
- 421 or 451 temporary errors: the receiving server is busy or throttling; a good relay retries automatically.
- Connection timed out: your network or hosting provider may be blocking the port; try 587 or 465.
SMTP or API?
SMTP is universal and easy to plug into existing software, such as WordPress, accounting tools and ERPs. An HTTP API gives developers more control and richer responses. Many teams use both. See SMTP relay vs email API and our Ghana-specific API vs SMTP comparison.
SMTP in everyday Ghanaian business tools
Many tools used by Ghanaian organisations send email via SMTP behind the scenes: WordPress and WooCommerce sites, school management systems, hotel booking engines, accounting packages and HR software. If customers report that “the system’s emails never arrive”, the cause is often a missing or badly configured SMTP setting. Pointing those tools at an authenticated relay usually fixes it.
A note on data
Email content passing through a relay is personal data under Ghana’s Data Protection Act, 2012 (Act 843), so choose a provider whose security you can explain. Mailpro hosts on private infrastructure in Switzerland, outside US jurisdiction. To monitor what your relay is doing, see SMTP statistics.