Unfortunately there is no means of being absolutely sure that your email messages will reach your recipients. We can do certain things like ensuring that we set SPF and DKIM DNS records but ultimately it’s best to leave bulk email sending to the experts. Particularly if you’re sending invoices or order details from your online store then it’s worth using a transactional email sending service (and don’t ever use the free email sending provided with your website host).
Transactional email sending services are designed for high deliverability in addition to being configured to send very large quantities of messages. Just because transactional email services are of great quality doesn’t mean that they are cost prohibitive for small Organisations; in fact, like Mailgun, some services have a generous free allowance per month. If you have a small Shopify or WooCommerce eCommerce store then you really have no excuse not to be taking advantage of a transactional email service.
Below are listed three of the better transactional email sending services.
Best for medium volume sending.
Mandrill offers 2,000 free sends. Thereafter a paid subscription is needed. Mandrill is best for medium and high volume senders.
Mandrill is a service by Mailchimp and is incredibly fast in sending and enjoys very high deliverability. As a Mailchimp expert I often get asked the difference between Mandrill and Mailchimp. Mailchimp offer various good articles about the difference.
Best for high volume sending.
Amazon Simple Email Service (SES) is a very widely used transactional email service and many other transactional email services use SES to send their clients email messages. SES is made for developers and, as such, usually requires more skill to setup than other similar services.
SES is relatively low cost and is an excellent service for high volume senders.
Best for low volume sending.
This is a service by Rackspace. Mailgun have a free service for low volume senders (I use the free Mailgun service). If you use WordPress and WooCommerce then the Mailgun plugin makes using Mailgun very easy.
Mailgun is a good choice for low volume senders due to the free account (the free account allows up to 10,000 send per month). Mailgun is however also used by large volume senders such as Xero who use Mailgun for their clients invoice, quote and receipt sending.