diff --git a/src/api.ts b/src/api.ts
index cfb446a..722dc70 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -1,5 +1,5 @@
+import { transformDurations } from "./duration";
 import { perform } from "./email";
-import type { EmailJob } from "./job";
 import { ConsoleLogger } from "./logger";
 
 export const main = (port: number) => {
@@ -10,7 +10,12 @@ export const main = (port: number) => {
 
       const url = new URL(req.url);
       if (req.method === "POST" && url.pathname === "/api/email") {
-        const job: EmailJob = await req.json();
+        const prevalidatedJob = transformDurations(await req.json());
+        if (prevalidatedJob._tag === "Left") {
+          return new Response(prevalidatedJob.left, { status: 400 });
+        }
+        const job = prevalidatedJob.right;
+        
         const jobInsensitive = structuredClone(job);
         jobInsensitive.from.username = "****REDACTED****";
         jobInsensitive.from.password = "****REDACTED****";
diff --git a/src/duration.ts b/src/duration.ts
index 3d1a44c..e8dc7d1 100644
--- a/src/duration.ts
+++ b/src/duration.ts
@@ -12,6 +12,7 @@ export enum DurationUnit {
   MINUTE,
   HOUR,
 }
+
 const durationUnitMap: Record<string, DurationUnit> = {
   ms: DurationUnit.MILLISECOND,
   milliseconds: DurationUnit.MILLISECOND,
@@ -153,3 +154,26 @@ export const parse = (duration: string): E.Either<string, Duration> => {
     E.map(build),
   );
 };
+
+export const transformDurations = (obj: any): E.Either<string, any> => {
+  const transform = (o: any): E.Either<string, any> => {
+    const entries = Object.entries(o);
+
+    for (let [key, value] of entries) {
+      if (key === "duration" && typeof value === "string") {
+        return parse(value);
+      } else if (typeof value === "object" && value !== null) {
+        const result = transform(value);
+        if (E.isLeft(result)) {
+          return result;
+        } else {
+          o[key] = result.right;
+        }
+      }
+    }
+
+    return E.right(o);
+  };
+
+  return transform(obj);
+}
diff --git a/src/email.ts b/src/email.ts
index 6ad05a0..906b86d 100644
--- a/src/email.ts
+++ b/src/email.ts
@@ -14,7 +14,7 @@ interface ImapClientI {
   connect: () => Promise<void>;
   getMailboxLock: (mailbox: string) => Promise<MailboxLockObject>;
   messageDelete: (uids: number[], opts: Record<string, any>) => Promise<boolean>;
-  close: () => void;
+  logout: () => Promise<void>;
 }
 
 type Email = {
@@ -26,13 +26,16 @@ type Email = {
 
 class ErrorWithLock extends Error {
   lock: O.Option<MailboxLockObject>;
-  constructor(message: string, lock?: MailboxLockObject) {
+  imap: O.Option<ImapClientI>;
+  constructor(message: string, lock?: MailboxLockObject, imap?: ImapClientI) {
     super(message);
     this.lock = O.fromNullable(lock);
+    this.imap = O.fromNullable(imap);
   }
 }
-const ToErrorWithLock = (lock?: MailboxLockObject) => (error: unknown) =>
-  new ErrorWithLock(error instanceof Error ? error.message : "Unknown error", lock);
+
+const ToErrorWithLock = (lock?: MailboxLockObject, imap?: ImapClientI) => (error: unknown) =>
+  new ErrorWithLock(error instanceof Error ? error.message : "Unknown error", lock, imap);
 
 /**
  * Generate a unique email.
@@ -203,19 +206,19 @@ export const perform = (
     // act.
     TE.tap(({ email }) => pipe(getSendImpl(from)(email), TE.mapLeft(ToErrorWithLock()))),
     TE.bind("imap", () => pipe(getImapImpl(to), TE.mapLeft(ToErrorWithLock()))),
-    TE.bind("mailboxLock", ({ imap }) => TE.tryCatch(() => imap.getMailboxLock("INBOX"), ToErrorWithLock())),
+    TE.bind("mailboxLock", ({ imap }) => TE.tryCatch(() => imap.getMailboxLock("INBOX"), ToErrorWithLock(undefined, imap))),
     // "assert".
     TE.bind("uid", ({ imap, email, mailboxLock }) =>
       pipe(
         findEmailUidInInboxImpl(imap, matchesEmailImpl(email), retries, interval),
-        TE.mapLeft(ToErrorWithLock(mailboxLock))
+        TE.mapLeft(ToErrorWithLock(mailboxLock, imap))
       )
     ),
     // cleanup.
     TE.bind("deleted", ({ imap, uid, mailboxLock }) =>
       TE.tryCatch(
         () => imap.messageDelete([uid], { uid: true }),
-        ToErrorWithLock(mailboxLock),
+        ToErrorWithLock(mailboxLock, imap),
       ),
     ),
     TE.fold(
@@ -223,10 +226,15 @@ export const perform = (
         if (O.isSome(e.lock)) {
           e.lock.value.release();
         }
+        if (O.isSome(e.imap)) {
+          const imap = e.imap.value;
+          return pipe(TE.tryCatch(() => imap.logout(), toError), TE.flatMap(() => TE.left(e)));
+        }
         return TE.left(e);
       },
-      ({ mailboxLock, deleted }) => {
+      ({ mailboxLock, deleted, imap }) => {
         mailboxLock.release();
+        imap.logout();
         return TE.right(deleted);
       }
     )
diff --git a/tst/email.spec.ts b/tst/email.spec.ts
index 7315816..e966030 100644
--- a/tst/email.spec.ts
+++ b/tst/email.spec.ts
@@ -31,7 +31,7 @@ const getMocks = () => {
     connect: mock(() => Promise.resolve()),
     getMailboxLock: mock(() => Promise.resolve(lock)),
     messageDelete: mock(() => Promise.resolve(true)),
-    close: mock(() => constVoid()),
+    logout: mock(() => Promise.resolve()),
   };
 
   const mockDependencies: Partial<EmailJobDependencies> = {
@@ -116,6 +116,7 @@ test("releases lock on left", async () => {
     TE.mapLeft(() => {
       expect(imap.getMailboxLock).toHaveBeenCalledTimes(1);
       expect(lock.release).toHaveBeenCalledTimes(1);
+      expect(imap.logout).toHaveBeenCalledTimes(1);
     }),
   )();
 });
@@ -131,6 +132,7 @@ test("releases lock on right", async () => {
     TE.map(() => {
       expect(imap.getMailboxLock).toHaveBeenCalledTimes(1);
       expect(lock.release).toHaveBeenCalledTimes(1);
+      expect(imap.logout).toHaveBeenCalledTimes(1);
     }),
     TE.mapLeft(() => expect(false).toBeTruthy()),
   )();