How can one ensure that emails sent from a local mail server do not end up in the recipient's spam folder?
To ensure that emails sent from a local mail server do not end up in the recipient's spam folder, you can set up SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) records for your domain. These records help to authenticate your emails and reduce the likelihood of them being marked as spam by recipient email servers. Additionally, make sure your email content is not triggering spam filters by avoiding spammy language and including relevant information.
// Example SPF record in DNS settings
"v=spf1 include:_spf.yourdomain.com ~all"
// Example DKIM record in DNS settings
"v=DKIM1; k=rsa; p=your_dkim_public_key"
// Example PHP code to set up SPF and DKIM headers in email
$headers = "From: Your Name <yourname@yourdomain.com>\r\n";
$headers .= "Reply-To: yourname@yourdomain.com\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";
$headers .= "SPF: pass\r\n";
$headers .= "DKIM-Signature: your_dkim_signature\r\n";
// Send the email
mail($to, $subject, $message, $headers);