email integration

* Nest email module with smtp, postmark and console log drivers
* react-email package

apps/server/src/integrations/mail/interfaces/mail.interface.ts

@@ -0,0 +1,30 @@
+import SMTPTransport from 'nodemailer/lib/smtp-transport';
+
+export enum MailOption {
+  SMTP = 'smtp',
+  Postmark = 'postmark',
+  Log = 'log',
+}
+
+export type MailConfig =
+  | { driver: MailOption.SMTP; config: SMTPConfig }
+  | { driver: MailOption.Postmark; config: PostmarkConfig }
+  | { driver: MailOption.Log; config: LogConfig };
+
+export interface SMTPConfig extends SMTPTransport.Options {}
+export interface PostmarkConfig {
+  postmarkToken: string;
+}
+export interface LogConfig {}
+
+export interface MailOptions {
+  mail: MailConfig;
+}
+
+export interface MailOptionsFactory {
+  createMailOptions(): Promise<MailConfig> | MailConfig;
+}
+
+export interface MailModuleOptions {
+  imports?: any[];
+}