Java implementation for e-mail address validation

We search for a expert to implement a email validation of a list of email addresses. As a result of the validation we need as much as possible details about the given e-mail. The goal is to reduce the manual effort of a call center by knowing if the given e-mail address is a valid or invalid one. Also it would be nice to know what type of error was the result of the e-mail validation. As a input you will get a XLSX list. Your implementation shall be in Apache POI and the column containing the e-mail address shall be configurable by a the column header name. (we provide already the cmd line parsing and integration for you, your job is only to handle the POI/Excel) We do not need a database, since we have a custom implementation. BUT your model classes have to properly designed to be later able to use it easily with a custom persistence layer. To ensure you are not a simple poster please add the result of seven power two on top of your application. As a result we expect to get a updated Excel file with the new columns which you need to provide for the end user to understand the status of the phone number validation. Ensure that your implementation has a component for XLSX reading, one for e-mail validation and one for XLSX writing. Ensure the components are independently usable! We prefer for e-mail Java Standards. As a runtime environment we expect to be runnable on: - in JavaEE 7 (wildfly 10) - Java 8 As the development environment we expect: - Eclipse Neon (no Netbeans, no Idea) - Maven3 Your delivery artefacts are: - eclipse full project(s) incl. configurations and settings (provided already) - the full source code - a fully working [login to view URL] to build the application as a single & runnable jar (provided already) - an proguard obfuscated single and runnable jar (with maven), so no one can easily access the code by reverse engineering - we share you a git source repository for delivering the milestones (provided already) What we do not want: - any public (web/rest) service which is doing the work. We want to have the data extraction fully in our code and on our machine running. With your application provide us following details: - delivery date for milestone 1 - a list in excel of statuses collected for the later e-mail validation (e.g. reg-ex failed, DNS wrong, SMTP command validation failed, SMTP sending, SMTP graylisting, ...) - working POI implementation to read the email column - delivery date for milestone 2 - working e-mail validation, no extraction of validation results into XLSX - delivery date for milestone 3 - working validation extraction and implemented XLSX writing Helpful information and readings may be this: Validation steps at least are required to test this: - e-mail syntax (regex or library) - the email against a list of bad email addresses (regex and for now hard coded bad e-mail addresses in a List<String>()) - the domain against a list of bad domains (regex and for now hard coded bad domains in a List<String>()) - a list of mailbox-only domains (regex) (regex and for now hard coded mailbox domains in a List<String>()) - whether or not the domain exists (DNS check) - whether there are MX records for the domain (DNS check) - through SMTP status codes whether or not a mailbox exists (SMTP status check) - through SMTP message sending (SMTP check) - overcome Greylisting (SMTP check) for more details about existing code and examples: [login to view URL]