Curumeru

What Curumeru is

Curumeru (クルメル) is an email delivery system from RAKUS Co., Ltd. that is built to be driven by other software. The site's title calls it an email delivery API and newsletter delivery API: a company connects its own system through a published API, or relays mail through Curumeru's SMTP servers, and Curumeru takes care of bulk sending, delivery tuning and result tracking. The home page says the API adds advanced email marketing functions to an existing system, and that the relay strengthens a company's mail infrastructure while keeping system modification costs down. A news item names it alongside 配配メール (Haihai Mail), RAKUS's other email delivery system.

The site lists the kinds of systems Curumeru sends for: membership management systems, recruitment and staffing systems, marketing automation, POS systems, web reservation systems and shopping carts. In each case the mail starts in the customer's own software, and Curumeru is the delivery layer behind it.

API integration

Curumeru publishes a set of APIs so that an external system can use it without anyone logging in. Among them are calls for uploading a delivery list, scheduling a delivery, canceling one, sending a test email, and retrieving error information, open information, URL click information and the list of sent emails. That covers the whole loop from sending to reading results.

The scheduled bulk delivery API (CreateNewMail) shows how it works in practice. The calling system passes a CSV file as the delivery list, which Curumeru registers as a list, and a From address that is not yet in the system is registered automatically. The body goes in html_part for HTML email or text_part for plain text. Each request sets:

• a connection password for API access
• the character encoding of the CSV and the request: UTF-8, Shift-JIS or EUC-JP
• the response format, CSV (the default) or XML
• the To and From addresses, an optional sender name and the subject
• a group code of up to 20 half-width alphanumeric characters for identifying the mail
• immediate or scheduled delivery; scheduled times must lie in the future, fall on 5-minute intervals, and can run from now until the end of the following year
• a report option that emails a report when the batch finishes, never, or only on errors; if the option is left out, the report is sent

The connection URL is built from the login URL that RAKUS gives each customer, so every account calls its own endpoint.

The call returns a mail ID that the system keeps to follow that send. Personalization uses customer data fields: writing ##field name## in the subject or body inserts each recipient's value, so a subject aimed at residents of one prefecture and a greeting by name both come from a single template. The replacement data can carry up to 100 columns.

The error codes are documented in full, so a developer can tell exactly why a request failed: wrong connection details, access from an IP address that is not permitted, too many API calls, a file of 30MB or more, attachments over 3MB in total, a subject longer than 900 characters, or a text line longer than 990 half-width characters (about 330 full-width).

Options and plans

Two capabilities are paid options. The attachment option allows up to 10 files per message, from attach_file_01 to attach_file_10, with a combined limit of 3MB. The multilingual delivery option adds Traditional Chinese, Simplified Chinese, Korean and other languages besides Japanese, all sent in UTF-8.

The news section records other additions over the years: a marketing operation support option for RAKUS's email systems, a business partnership with Lightup Co., a limited-time zero-yen special plan for IT startups that wanted API integration, and a plan specialized for large-volume delivery. The home page says that plan sends even image-heavy HTML email quickly.

SMTP relay and deliverability

For companies that would rather not write integration code, the mail relay routes mail through Curumeru servers dedicated to bulk sending. The site says a company only has to change its existing mail server setting to Curumeru, so the mail infrastructure gets stronger without a costly system rebuild.

To avoid receiving blocks by mobile carriers and internet providers, Curumeru spreads delivery across IP addresses and stops sending to addresses that return errors, and the site credits that tuning for its high deliverability. Error information can then be pulled through the API, so the calling system can update its own records.

Pricing

Pricing is made up of an initial fee plus a monthly fee, both varying with the plan and the scale of delivery. The site publishes no price table; prospects request materials or contact the company for a figure.

Support and security

Curumeru has a dedicated support site, and the home page says inquiries are answered within 3 hours on average. The site lists regional phone lines, including numbers in Tokyo, Nagoya and Fukuoka.

According to the site, the servers sit in one of Japan's leading data centers with outstanding disaster resistance, and security features include encrypted communication and access restrictions by IP address; the API itself rejects calls from IP addresses that are not permitted. RAKUS states that protecting the customer information it holds, such as newsletter readers' personal data, is a company-wide duty. The footer carries a contact point for spam complaints and the privacy policy.

Customer example

Brain Lab, a developer of recruitment systems, says it adopted Curumeru when its users' demand for bulk sending grew. Among the email systems that offered the API integration it needed, Curumeru was the cheapest, and the rollout went smoothly. The site keeps a longer list of adopting companies on its case studies page.

Who it suits

Curumeru suits Japanese companies that run their own membership, recruitment, reservation, POS or e-commerce systems and want to add bulk and scheduled email, with open, click and error data flowing back through the API. Its support for Shift-JIS and EUC-JP as well as UTF-8 helps with older Japanese systems, and the SMTP relay suits companies that only want to swap their outbound mail server. It is a delivery engine meant to be driven from another system rather than a campaign tool for a marketer at a dashboard, and the site and support are in Japanese.